ANTI-FOULING SYSTEM, CONTROLLER AND METHOD OF CONTROLLING THE ANTI-FOULING SYSTEM

Abstract

An anti-fouling system (1) for use with a wet compartment (10) having at least one inlet opening (11) for allowing water to enter the compartment (10) is configured to receive and operate at least one anti-fouling source for emitting anti-fouling light in order to keep at least one surface (26) as present in the compartment (10) free from biofouling. The system (1) comprises a controller (50) for controlling operation of the at least one anti-fouling source (30), the controller (50) being configured to determine at least one operation parameter of the at least one anti-fouling source (30) in relation to at least one of at least one water-related parameter, at least one surface-related parameter and at least one opening-related parameter.

Claims

1. An anti-fouling system, designed to be used with a wet compartment having at least one inlet opening for allowing water to enter the wet compartment, the anti-fouling system being configured to receive and operate at least one anti-fouling source for emitting anti-fouling light in order to keep at least one surface as present in the wet compartment free from biofouling, and the anti-fouling system comprising a controller for controlling operation of the at least one anti-fouling source when the anti-fouling source is received in the anti-fouling system and the anti-fouling system is used with the wet compartment, the controller being configured to determine at least one operation parameter of the at least one anti-fouling source in relation to at least one of: at least one surface-related parameter; at least one opening-related parameter; a rate of a flow of water along the surface to be kept free from biofouling; a temperature of water inside the wet compartment; an algal content of water inside the wet compartment; a concentration of copper ions in water inside the wet compartment; a concentration of chlorine in water inside the wet compartment; a temperature of the surface to be kept free from biofouling; and a rate of a flow of water through the at least one inlet opening of the wet compartment, and the anti-fouling system also comprising at least one sensor for detecting an actual value of the at least one parameter, the sensor being associated with the controller so as to be capable of providing feedback about the value to the controller.

2. (canceled)

3. (canceled)

4. The system according to claim 1, particularly designed to be used with a wet compartment of which the at least one inlet opening is adapted to be in one of an opened state and a closed state, wherein the controller is configured to control the at least one anti-fouling source for providing a dose of anti-fouling light followed by switching off the anti-fouling source or only operating the anti-fouling source to a minimal extent when the opening is put from the opened state to the closed state, and to keep the anti-fouling source in a state of no or minimal activity, at least during a predetermined period of time as long as the closed state is maintained.

5. (canceled)

6. The system according to claim 1, wherein the controller is configured to determine an intensity of anti-fouling light to be emitted by the at least one anti-fouling source through time in relation to the at least parameter.

7. The system according to claim 1, wherein the controller comprises a memory in which a fouling control model configured to determine output related to the at least one operation parameter of the at least one anti-fouling source in relation to input related to the at least one parameter is stored.

8. The system according to claim 1, designed for receiving and operating at least one anti-fouling source for emitting ultraviolet light.

9. The system according to claim 1, wherein the surface to be kept free from biofouling includes an interior surface of an actual structure of the wet compartment.

10. The system according to claim 1, particularly designed to be used with a wet compartment in which a functional unit is arranged, wherein the surface in the wet compartment to be kept free from biofouling includes an exterior surface of the functional unit.

11. A vessel comprising a wet compartment having at least one inlet opening for allowing water to enter the wet compartment and the anti-fouling system according to claim 1.

12. A vessel comprising a wet compartment having at least one inlet opening for allowing water to enter the wet compartment and the anti-fouling system according to claim 1, and further comprising machinery, a functional unit of the machinery being arranged in the wet compartment, wherein the surface in the wet compartment to be kept free from biofouling includes at least one of an interior surface of the actual structure of the wet compartment and an exterior surface of the functional unit of the machinery.

13. A method for controlling operation of at least one anti-fouling source of an anti-fouling system when the anti-fouling system is used with a wet compartment having at least one inlet opening for allowing water to enter the wet compartment, the at least one anti-fouling source being configured to emit anti-fouling light in order to keep at least one surface as present in the wet compartment free from biofouling, and the method involving a step of determining at least one parameter of the operation of the at least one anti-fouling source in relation to at least one of: at least one surface-related parameter; at least one opening-related parameter; a rate of a flow of water along the surface to be kept free from biofouling; a temperature of water inside the wet compartment; an algal content of water inside the wet compartment; a concentration of copper ions in water inside the wet compartment; a concentration of chlorine in water inside the wet compartment; a temperature of the surface to be kept free from biofouling; and a rate of a flow of water through the at least one inlet opening of the wet compartment, and a step of detecting an actual value of the at least one parameter.

14. The method according to claim 13, wherein the anti-fouling system is particularly used with a wet compartment of which the at least one inlet opening is adapted to be in one of an opened state and a closed state, wherein the at least one anti-fouling source is controlled for providing a dose of anti-fouling light followed by switching off the anti-fouling source or only operating the anti-fouling source to a minimal extent when the opening is put from the opened state to the closed state, and wherein the anti-fouling source is kept in a state of no or minimal activity, at least during a predetermined period of time as long as the closed state is maintained.

15. A controller for controlling operation of at least one anti-fouling source of an anti-fouling system when the anti-fouling system is used with a wet compartment having at least one inlet opening for allowing water to enter the wet compartment, the at least one anti-fouling source being configured to emit anti-fouling light in order to keep at least one surface as present in the wet compartment free from biofouling, and the controller being configured to determine at least one operation parameter of the at least one anti-fouling source in relation to at least one of: at least one surface-related parameter; at least one opening-related parameter; a rate of a flow of water along the surface to be kept free from biofouling; a temperature of water inside the wet compartment; an algal content of water inside the wet compartment; a concentration of copper ions in water inside the wet compartment; a concentration of chlorine in water inside the wet compartment; a temperature of the surface to be kept free from biofouling; and a rate of a flow of water through the at least one inlet opening of the wet compartment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The invention will now be explained in greater detail with reference to the figures, in which equal or similar parts are indicated by the same reference signs, and in which:

[0041] FIG. 1 diagrammatically shows a wet compartment, a functional unit arranged in the wet compartment, lamps for casting anti-fouling light over the exterior surface of the functional unit, an ICAF system arranged in the wet compartment, a controller for controlling operation of the lamps and the ICAF system, and a number of sensors coupled to the controller; and

[0042] FIG. 2 is a block diagram for illustrating possibilities in respect of control of operation of the lamps.

DETAILED DESCRIPTION OF EMBODIMENTS

[0043] FIG. 1 diagrammatically shows a wet compartment 10 as present in a ship, and furthermore shows a box cooler 20 comprising a plurality of tubes 21 for containing and transporting a fluid to be cooled in their interior. The wet compartment 10 has a number of inlet openings 11 for allowing water to enter in and a number of outlet openings 12 for allowing water to flow out. The box cooler 20 is enabled to perform its function of cooling fluid by exposing the tubes 21 of the box cooler 20 to water from the immediate outside environment of the ship, which will hereinafter be referred to as seawater. In particular, the tubes 21 of the box cooler 20 are accommodated inside the wet compartment 10, the wet compartment 10 being delimited by a portion of the ship's hull 101 and partition plates 102, 103. Both the inlet openings 11 and the outlet openings 12 of the wet compartment 10 are arranged in the ship's hull 101, wherein the inlet openings 11 serve for allowing seawater to enter the wet compartment 10 from the outside, and wherein the outlet openings 12 serve for allowing seawater to exit the wet compartment 10 and to flow to the outside of the ship.

[0044] In the shown example, the tubes 21 of the box cooler 20 have a curved shape, particularly a U shape, comprising a curved bottom portion 21a and two substantially straight leg portions 21b extending substantially parallel to each other. During operation of the box cooler 20, fluid to be cooled, i.e. hot fluid, flows through the tubes 21, while seawater enters the wet compartment 10 through the inlet openings 11. On the basis of the interaction of the seawater with the tubes 21 containing the hot fluid, it happens that the tubes 21 and the fluid are cooled, and that the seawater heats up. On the basis of the latter effect, and possibly also motion of the ship, a natural flow of seawater is obtained in the wet compartment 10, wherein cold seawater enters the wet compartment 10 through the inlet openings 11, and wherein seawater at a higher temperature exits the wet compartment 10 through the outlet openings 12. Advantageously, the tubes 21 are made of a material having good heat transferring capabilities, such as copper. For the sake of clarity, it is noted that in FIG. 1, for illustration purposes, another orientation of the wet compartment 10 and the box cooler 20 associated with the wet compartment 10 is shown than the orientation which is known from practice, and which involves an upright position of the U shaped tubes 21 of the box cooler 20. In any case, the invention is in no way restricted to a particular orientation of components.

[0045] Top sides of the leg portions 21b of the tubes 21 are at a similar level in view of the fact that the top sides of the leg portions 21b of the tubes 21 are connected to a common tube plate 22. The tube plate 22 is covered by a fluid header 23 comprising at least one inlet stub 24 and at least one outlet stub 25 for the entry and the exit of fluid to and from the tubes 21, respectively. Hence, the leg portions 21b of the tubes 21 which are at the side of the inlet stub 24 are at the highest temperature, while the leg portions 21b of the tubes 21 which are at the side of the outlet stub 25 are at a lower temperature, and the same is applicable to the fluid flowing through the tubes 21.

[0046] During the continuous cooling process of the tubes 21 and the fluid as present in the tubes 21, any microorganisms being present in the seawater tend to attach to the tubes 21, especially the portions of the tubes 21 which are at an ideal temperature for providing a suitable environment for the microorganisms to live in, the phenomenon being known as biofouling. In order to prevent this phenomenon, it is proposed to use at least one lamp 30 for casting anti-fouling light on an exterior surface 26 of the tubes 21. For example, the light may be UVC light, which is known to be effective for realizing anti-fouling. In the shown example, a number of lamps 30 are used, each of the lamps 30 being arranged in the wet compartment 10, in the same area as the tubes 21, which does not alter the fact that numerous other possibilities exist as well in respect of the positioning of the lamps 30. Besides the use of the lamps 30, other measures may be taken for avoiding biofouling of the exterior surface 26 of the tubes 21. FIG. 1 illustrates an optional additional use of a so-called ICAF system 40 for producing copper ions.

[0047] The operation of the lamps 30 is controlled by means of a controller 50. The controller 50 is configured so as to realize operation of the lamps 30 in an optimal manner, namely by determining at least one operation parameter on the basis of a process in which at least one aspect of an actual condition of the wet compartment 10 is taken into account, especially at least one aspect related to the water as may be present in the compartment 10 and/or to the surface 26 to be kept free from biofouling and/or to the opening status of the inlet openings 11. FIG. 1 illustrates the fact that one or more sensors may be used for detecting an actual value of a parameter to be used in the process of determining how to control the lamps 30. In the shown example, one sensor 51 is provided for detecting a water-related parameter, whereas another sensor 52 is provided for detecting a surface-related parameter. Dashed lines extending between the controller 50 and the sensors 51, 52, between the controller 50 and the ICAF system 40, between the controller 50 and the lamps 30, and between the controller 50 and the inlet openings 11, respectively, represent the connections as present between the controller 50 and the various components as mentioned, which enable communication between the controller 50 and the components, so that an intelligent system 1 is obtained in which anti-fouling effects can be achieved at a minimum load of the lamps 30, which promotes a prolonged lifetime of the lamps 30, to mention one advantage. The controller 50 may be configured to operate all lamps 30 in a similar manner, but it is also possible that lamps 30 are controlled individually, which may be advantageous in situations in which it is desirable to have sophisticated control aimed at optimization at a level of various positions in the wet compartment 10.

[0048] The controller 50 may comprise a memory 60 for storing a fouling control model, so that appropriate values of at least one operation parameter of the lamps 30 can be determined on the basis of any possible input. In particular, such a fouling control model may be designed on the basis of knowledge about relations between various input parameters and output parameters which are optimal as far as anti-fouling effectiveness on the one hand and prevention of unnecessary high load of the lamps 30 on the other hand is concerned.

[0049] FIG. 2 illustrates the possible use of various sensors 51, 52, 53, 59 in the process of determining the at least one operation parameter of the lamps 30. Furthermore, FIG. 2 illustrates the fact that the one or more actual values as detected by the sensors 51, 52, 53, 59 may be supplied as input to a fouling control model 61 as mentioned in the foregoing. The fouling control model 61 describes a relation between biofouling and at least one of at least one water-related parameter, at least one surface-related parameter and at least one opening-related parameter, and the necessary lamp output to counteract the biofouling. Thus, based on the input provided by the sensors 51, 52, 53, 59, the fouling control model 61 defines optimum drive conditions of the lamps 30 and provides the at least one operation parameter associated with those optimum drive conditions to control electronics 31 of the lamps 30.

[0050] The extent to which water causes biofouling of a surface 26 depends on several physic-chemical and biological parameters. Examples are Total Organic Carbon (TOC), temperature, light, dissolved oxygen, pH, nutrients, dissolved organic matters, dissolved inorganic matters, suspended matter and shear forces. If the biofouling is caused by algal blooms, another parameter which can be used as an alternative indication of the biofouling potential of water is the algal content of the water. If algal concentrations exceed a certain value, the amount of algae is large enough to release organics triggering biofouling. Another similar indicator is the content of algae measured as chlorophyll-a. Water with a high amount chlorophyll-a can be expected to have very high biofouling propensity.

[0051] Besides the fouling control model 61, a lamp lifetime model 62 describing a relation between load of the lamps 30 and lifetime of the lamps 30 may also be used in the anti-fouling system 1. Assuming that the control electronics 31 are combined with electronics for monitoring load and behavior of the lamps 30, input for defining the expected lifetime of the lamps 30 can be obtained. All in all, based on the output of the sensors 51, 52, 53, 59 and the information regarding the behavior of the lamps 30, it is possible to determine the optimal lamp load (in terms of power, duty cycle, etc.) needed to counteract biofouling at a maximum lifetime of the lamps 30, by using the fouling control model 61 and the lamp lifetime model 62. Monitoring the lamp load and behavior also provides an indication of the expected end-of-life of the lamps 30.

[0052] In the anti-fouling system 1 as described in the foregoing and illustrated in the figures, any water-related parameter and/or surface-related parameter and/or opening-related parameter may be used in a process of finding a way of driving the lamps 30 for achieving the anti-fouling effect as desired at minimum load. An example of a surface-related parameter is the temperature of the surface 26. An example of an opening-related parameter is a state of the inlet openings 11, assuming that this state may vary between opened and closed, to which end suitable means such as valves may be used.

[0053] According to one possibility, the controller 50 is configured to active the ICAF system 40 only in situations in which the lamps 30 are known to be less effective, probably not effective enough for totally avoiding biofouling. An example of such situations is a situation in which the water has a low transparency to the ultraviolet light. According to another possibility, the controller 50 is configured so as to alternate the application of the lamps 30 and the ICAF system 40, in order to increase the lifetime of both the lamps 30 and the ICAF system 40 and to reduce the need for maintenance.

[0054] The controller 50 may furthermore be configured to take special action when the inlet openings 11 are put from an opened state to a closed state for a period of time. This may occur when the ship is in a harbor, for example. The special action may involve driving the lamps 30 at relatively high power during a time which is long enough for achieving a sterilizing effect on any water as may be present in the wet compartment 10. After that time, the lamps 30 may basically be kept in an inactive condition as long as the inlet openings 11 are kept in the closed state. There is also no need for driving the ICAF system 40 during that time. In fact, this way of doing is applicable to every situation in which there is no need to operate the box cooler 20, which is generally a situation in which the ship's engine is off.

[0055] Numerous other possibilities than the ones explicitly explained above exist within the concept of controlling operation of the lamps 30 in dependency of one or more parameters representing an actual condition of the wet compartment 10 and/or one or more components associated therewith. The exterior surface 26 of tubes 21 of a box cooler 20 is just one example of a surface as may be present in a wet compartment 10, which is to be kept free from biofouling. An interior surface 104 of the portion of the ship's hull 101 associated with the wet compartment 10 and/or the partition plates 102, 103 is another feasible example of such a surface. Furthermore, ultraviolet light is just one example of a type of light which is suitable to be used for anti-fouling purposes.

[0056] The invention is applicable to a ship as described in the foregoing, to any other type of vessel comprising a wet compartment 10, or to any other arrangement comprising a wet compartment 10, when there is a need for keeping a surface as present in the wet compartment 10 free from biofouling. The ship or other type of vessel, or the arrangement in a more general sense may comprise more than one wet compartment 10 to which the invention is applied, i.e. in which control of lamps 30 and/or other anti-fouling sources is based on feedback/information about one or more parameters relating to water as may be present in the wet compartment 10 and/or the surface 26, 104 to be kept clean and/or the state of the inlet openings 11.

[0057] It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims. It is intended that the invention be construed as including all such amendments and modifications insofar they come within the scope of the claims or the equivalents thereof While the invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The invention is not limited to the disclosed embodiments. The drawings are schematic, wherein details that are not required for understanding the invention may have been omitted, and not necessarily to scale.

[0058] Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word comprising does not exclude other steps or elements, and the indefinite article a or an does not exclude a plurality. The term comprise as used in this text will be understood by a person skilled in the art as covering the term consist of. Hence, the term comprise may in respect of an embodiment mean consist of, but may in another embodiment mean contain/include at least the defined species and optionally one or more other species. Any reference signs in the claims should not be construed as limiting the scope of the invention.

[0059] Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise. Thus, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0060] The term substantially as used in this text will be understood by a person skilled in the art as being applicable to situations in which a certain effect is intended which can be fully realized in theory but which involves practical margins for its factual implementation. Examples of such an effect include a parallel arrangement of objects and a perpendicular arrangement of objects. Where applicable, the term substantially may be understood such as to be an adjective which is indicative of a percentage of 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%.

[0061] In view of the fact that biofouling does not only occur at sea, but also in rivers, lakes and the like, the invention is generally applicable in a context in which a wet compartment 10 is present, which may be filled with any kind of water. This context may be the context of a vessel, as mentioned earlier, or even more general, the context of marine objects such as oilrigs, or other types of buildings in or next to the ocean, which does not alter the fact that the invention may also be applicable in the context of a domestic appliance in which water is used during operation thereof, for example, such as a coffee maker or a water disinfector, or another context which may be totally different from the context of marine objects.

[0062] In respect of the possible application of the invention in the context of a wet compartment 10 accommodating a box cooler 20, it is noted that the invention is in no way restricted to the layout of the box cooler 20 as described in the foregoing and illustrated in FIG. 1 as an example. It is clear to a person skilled in the art that the features of the invention are not dependent on any feature of the surface 26, 104 to be protected against the fouling effect of water. Also, the application of ultraviolet lamps 30 for realizing anti-fouling effects during operation thereof is just one of the many possibilities existing within the framework of the invention. In the embodiments of the invention as shown, the wet compartment 10 is used for accommodating the tubes 21 of a box cooler 20, which tubes 21 are to be considered as just one example of a functional unit. Additionally or alternatively, the wet compartment 10 may be used for accommodating one or more other objects/units, but may also be empty, i.e. does not need to contain any objects/units. For example, in case the anti-fouling system is applied in a ship, the wet compartment 10 may be a so-called sea chest for taking in ballast water or fire extinguishing water.

[0063] In the shown embodiment of the wet compartment 10, a number of inlet openings 11 for allowing water to enter the wet compartment 10 and a number of outlet openings 12 for allowing water to exit the wet compartment 10 are present. That does not alter the fact that the option of only a single opening being present, wherein the opening has a combined function of being an inlet opening and an outlet opening, is also covered by the invention. For the sake of completeness, it is noted that it is not essential to have at least one outlet opening 12, on the basis of the fact that practical cases exist in which there is no need for emptying the wet compartment 10 through one or more outlet openings 12 after initial filling of the wet compartment 10.

[0064] In the context of the invention, the term compartment should preferably be understood such as to mean something like a separate room, basin, section, or chamber. The adjective wet is used to indicate that the compartment 10 is intended to be at least partially filled with water, which does not alter the fact that the compartment 10 may be in a dry condition under appropriate circumstances.

[0065] Summarizing, an anti-fouling system 1, designed to be used with a wet compartment 10 having at least one inlet opening 11 for allowing water to enter the wet compartment 10 is configured to receive and operate at least one anti-fouling source 30 for emitting anti-fouling light in order to keep at least one surface 26, 104 as present in the wet compartment 10 free from biofouling. For example, the at least one anti-fouling source 30 for use in the anti-fouling system 1 may be adapted to irradiate the surface 26, 104 with ultraviolet light. The anti-fouling system 1 comprises a controller 50 for controlling operation of the at least one anti-fouling source 30 when the anti-fouling source 30 is received in the anti-fouling system 1 and the anti-fouling system 1 is used with the wet compartment 10, the controller 50 being configured to determine at least one operation parameter of the at least one anti-fouling source in relation to at least one of at least one water-related parameter, at least one surface-related parameter and at least one opening-related parameter so as to take into account as least one aspect of an actual situation prevailing in the wet compartment 10 in a process of setting the at least one operation parameter. On the basis of the special configuration of the controller 50, it is possible to avoid unnecessary high load of the at least one anti-fouling source 30 in the process of preventing biofouling, which is beneficial to the lifetime of the anti-fouling source 30.