The present disclosure relates to a support assembly for a self-containing cryogenic tank. Moreover, the present disclosure relates to a containment assembly for a self-containing cryogenic tank. Furthermore, the present disclosure relates to a vessel. Additionally, the present invention relates to a method for evaluating the tightness of a drip tray of a support assembly.
A cryogenic tank is a tank that is adapted to contain a cryogenic fluid, i.e. a relatively cold fluid such as liquefied natural gas (LNG) or the like. The cryogenic tank may for instance be integrated in an enclosing structure, such as the hull of a ship, or it may be a self-containing tank.
A self-containing tank may preferably be provided in a structure adapted to accommodate the tank. Purely by way of example, a self-containing tank may be provided within a ship or on a deck of a ship. However, a self-containing tank may also be provided in other types of structures, such as a building or the like.
Preferably, a self-containing cryogenic tank is provided on a support assembly. FR 2659619 discloses an example of ship that is provided with a support assembly for a self-containing cryogenic tank. The '619 support assembly comprises a drip tray adapted to be located beneath the cryogenic tank. Moreover, '619 discloses that an insulating layer is placed between the drip tray and an inner portion of the ship's hull.
Furthermore, '619 teaches that the tank is attached to the ship by means of an attachment arrangement that comprises a plurality of upper steel protrusions each one of which extending downwards from the bottom of the self-containing cryogenic tank. Each one of the upper steel protrusion is adapted to rest on a corresponding lower steel protrusion extending from the inner portion of the ship's hull.
Although the above discussed attachment means may provide appropriate attachment capabilities as such, there are problems associated with the '619 support assembly. For instance, there is a risk that a thermal bridge could occur between the self-containing cryogenic tank and the ship.
One object of the disclosure is to reduce or ameliorate at least one of the disadvantages of the prior art systems and/or methods, or to provide a useful alternative.
This object is achieved by a support assembly according to claim 1.
As such, the present disclosure relates to a support assembly for a self-containing cryogenic tank. The support assembly comprises a first thermally insulating layer and an impermeable layer located at least partially above the first thermally insulating layer. The impermeable layer is adapted to form a drip tray for the cryogenic tank.
According to the present disclosure, the support assembly further comprises a second thermally insulating layer located at least partially above the impermeable layer, the second thermally insulating layer being adapted to support the cryogenic tank.
By virtue of the presence of the second thermally insulating layer, the risk of obtaining a thermal bridge between the self-containing cryogenic tank and the structure beneath the first thermally insulating layer is reduced. Moreover, the support assembly according to claim 1 could possibly also be easier to install and more robust than a prior art support assembly.
As used herein, the expression “thermally insulating layer” relates to a layer that has a relatively low coefficient of thermal transmittance, i.e. U-value. Purely by way of example, at least one, though preferably both, of the first thermally insulating layer and the second thermally insulating layer has an average U-value that is less than 10 W/m2K, preferably less than 4 W/m2K, more preferred less than 1 W/m2K.
As used herein, the expression “cryogenic tank” relates to a tank that is adapted to contain a cryogenic liquid, i.e. a liquid that has a low temperature. Purely by way of example, the liquid may have a temperature of −30° C. or less.
Moreover, as used herein, the expression “self-containing” encompasses any tank that does not have to be integrated with any additional enclosing structure in order to be adapted to contain a fluid. Purely by way of example, a self-containing tank within the above meaning may be adapted to be moved in relation to the structure in which it is adapted to be located. A self-containing tank may also be referred to as a self-supporting tank.
Optionally, the second thermally insulating layer is adapted to support at least 50%, preferably at least 70%, more preferred all, of the weight of the cryogenic tank. Thus, the second support layer is optionally adapted to carry a large portion of the weight of the tank. Preferably, the second thermally insulating layer is adapted to support at least 50%, preferably at least 70%, more preferred all, of the weight of the full cryogenic tank, i.e. when containing the cryogenic liquid.
Optionally, the drip tray is sized and configured such that, when the support assembly supports the cryogenic tank, a vertical projection of the circumference of a bottom of the self-containing cryogenic tank down to the drip tray is accommodated within the circumference of the drip tray.
As such, the drip tray may optionally have a size and position such that it is adapted to collect a leak from at least the bottom of the tank irrespective of the position of the leakage in the bottom.
Optionally, the first thermally insulating layer and/or the second thermally insulating layer comprises a plurality of thermally insulating panels that are arranged side-by-side. Purely by way of example, a thermally insulating panel may have a U-value that is less than 5 W/m2K, preferably less than 0.5 W/m2K, more preferred less than 0.1 W/m2K.
By the provision of thermally insulating panels, the transfer of relative motions between the cryogenic tank and the body onto which the support assembly may be resting could be reduced. For instance, if the cryogenic tank is located in or on a ship, the provision of the thermally insulating panels implies that e.g. deflections of the ship's hull are at least not fully transferred to the cryogenic tank. This in turn implies that the cryogenic tank may be subjected to moderate loads even when the ship hosting the cryogenic tank is deflected.
Optionally, the support assembly further comprises spacer means adapted to provide a space between at least two of the thermally insulating panels.
Optionally, the spacer means comprises a wood panel, preferably a plywood panel.
Optionally, at least one of the thermally insulating panels comprises a glass fibre reinforced polyurethane foam.
Optionally, the impermeable layer comprises a SUS membrane, preferably a stainless steel membrane. As used herein, the abbreviation “SUS” means Steel Use Stainless.
Optionally, the support assembly further comprises a frame adapted to at least partially accommodate the first thermally insulating layer, the second thermally insulating layer and the impermeable layer.
Optionally, the support assembly further comprises load distributing means, adapted to be located between the second thermally insulating layer and the cryogenic tank.
The load distributing means may be adapted to distribute loads from the cryogenic tank to the second thermally insulating layer. As such, any local loads that may possibly be imparted on the load distributing means from the cryogenic tank may be distributed to a larger area of the second thermally insulating layer. Preferably, the load distributing means may also have a relatively low friction coefficient in order to allow a displacement of at least a portion of the cryogenic tank in relation to e.g. the second thermally insulating layer.
Optionally, the load distributing means comprises a metal panel, preferably a plurality of metal panels.
Optionally, the support assembly further comprises a leak drain conduit assembly at least partially extending through the impermeable layer. As such, should a leakage occur in the tank, the fluid thus leaked may firstly enter the drip tray and thereafter be guided from the drip tray through the leak drain conduit assembly.
Optionally, the support assembly further comprises a tray leakage test assembly comprising a temperature sensor located outside the impermeable layer such that at least a portion of the first thermally insulating layer is located between the sensor and the impermeable layer. The tray leakage test assembly may enable that the tightness of the drip tray of the support assembly may be evaluated, e.g. occasionally and/or on a regular basis.
Optionally, the tray leakage test assembly comprises a plurality of temperature sensors each one of which being located outside the impermeable layer such that at least a portion of the first thermally insulating layer is located between the sensor and the impermeable layer.
Optionally, the support assembly further comprises an attachment means adapted to be engaged with a portion of the cryogenic tank to thereby limit a displacement of the cryogenic tank, relative to the support assembly, in at least one direction.
Optionally, the attachment means comprises a cavity adapted to receive a tank protrusion of the cryogenic tank.
Optionally, the attachment means is configured such that when it receives the tank protrusion, a gap is formed, in at least one direction of a vertical and horizontal direction, between the tank protrusion and the attachment means.
Optionally, the support assembly comprises a foundation for the attachment means. The foundation comprises a first foundation portion, located beneath the impermeable layer, and a second foundation portion, located above the impermeable layer.
Optionally, the foundation is located at least partially within the circumference of the drip tray. By virtue of the provision of the foundation within the circumference of the drip tray, the risk of obtaining a thermal bridge from the self-containing cryogenic tank to a structure outside the support assembly may be reduced.
Optionally, the first foundation portion is attached to the second foundation portion via the impermeable layer, preferably by a bolt joint.
Optionally, the first foundation portion is attached to the frame, preferably by a bolt joint.
Optionally, the first foundation portion and/or the second foundation portion is made of wood, preferably hard wood. Wood, preferably hard wood, may have an appropriate strength, but also an appropriate thermal insulating capacity in order to be a suitable material for the first and/or second foundation portion.
A second aspect of the present disclosure relates to a containment assembly for a self-containing cryogenic tank. The containment assembly comprises a support assembly according to the first aspect of the present disclosure and a tank cover. The tank cover is adapted to be connected to the support assembly to thereby define a closed volume adapted to accommodate the cryogenic tank.
Optionally, the assembly further comprises sealing means adapted to provide a seal between the support assembly and the tank cover.
Optionally, the containment assembly further comprises a tank leakage test assembly adapted to detect a leakage from the tank.
Optionally, the tank leakage test assembly comprises a gas detector.
Optionally, the containment assembly comprises the tank leakage test assembly in addition to the tray leakage test assembly.
A third aspect of the present disclosure relates to a tank assembly comprising a cryogenic tank and a support assembly according to the first aspect of the present disclosure and/or a containment assembly according to the second aspect of the present disclosure.
A fourth aspect of the present disclosure relates to a vessel comprising a support assembly according to the first aspect of the present disclosure and/or a containment assembly according to the second aspect of the present disclosure and/or a tank assembly according to the third aspect of the present disclosure.
Optionally, the cryogenic tank is located in a vessel portion of the vessel. The cryogenic tank is configured such that a deflection of the vessel portion results in a corresponding deflection of the cryogenic tank.
A fifth aspect of the present disclosure relates to a method for evaluating the tightness of a drip tray of a support assembly for a self-containing cryogenic tank. The support assembly comprises a first thermally insulating layer and an impermeable layer located at least partially above the first thermally insulating layer. The support assembly comprises a temperature sensor located outside the impermeable layer such that at least a portion of the first thermally insulating layer is located between the sensor and the impermeable layer. The impermeable layer at least partially forms the drip tray. The method comprises:
Optionally, the support assembly comprises a plurality of temperature sensors each one of which being located outside the impermeable layer such that at least a portion of the first thermally insulating layer is located between the sensor and the impermeable layer. Moreover, the method optionally comprises determining a value indicative of the temperature in the vicinity of each one of the temperature sensors.
Optionally, the fluid is introduced from a fluid source that is separate from the cryogenic tank.
Optionally, the fluid has a temperature which is lower than the temperature of the ambient environment, preferably the fluid is liquid nitrogen.
Optionally, the value indicative of the temperature comprises a temperature in the vicinity of the temperature sensor, or in the vicinity of each one of the plurality of temperature sensors if the support assembly comprises a plurality of sensors. The method further comprises:
Optionally, the value indicative of the temperature comprises a temperature change rate in the vicinity of the temperature sensor, or in the vicinity of each one of the plurality of temperature sensors if the support assembly comprises a plurality of sensors.
Optionally, the method further comprises:
With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples.
In the drawings:
It should be noted that the appended drawings are not necessarily drawn to scale and that the dimensions of some features of the present invention may have been exaggerated for the sake of clarity.
The invention will, in the following, be exemplified by embodiments. It is to be understood, however, that the embodiments are included in order to explain principles of the invention and not to limit the scope of the invention defined by the appended claims.
As a non-limiting example, the volume of the self-containing cryogenic tank 12 may be in the range of 100-2000 m3, preferably within the range of 500-1500 m3.
Moreover,
Moreover,
Preferably, the drip tray 18 comprises a drip tray base portion 18′ and a drip tray rim portion 18″. The drip tray rim portion 18″ has preferably an extension which is at least partially in parallel with the vertical direction V. The drip tray base portion 18′ and the drip tray rim portion 18″ may be connected to one another so as form a tray that can collect and/or contain a fluid. It should be noted that the drip tray 18 could preferably be an open tray such as the implementation of the drip tray 18 illustrated in
As a non-limiting example, the drip tray 18 may be adapted to store leaked fluid, i.e. any fluid that may leak from the self-containing cryogenic tank 12, for a predefined time period, such as 15 days or more, without damaging any structure that surrounds the support assembly 10.
To this end, though again only as a non-limiting example, at least one of the first thermally insulating layer 14 and the second thermally insulating layer 20 may have thermally insulating properties that allows leaked fluid to be stored in the drip tray 18 for a predetermined time period without adversely affecting the structure surrounding the support assembly 10.
As a non-limiting example, the leaked fluid that may be at least temporarily contained in the drip tray 18 may be evaporated and ventilated by purging the drip tray 18 with a gas, such as nitrogen gas.
Purely by way of example, the second thermally insulating layer 20, which will be discussed in more detail hereinbelow, may have an absorbing capacity, i.e. the second thermally insulating layer 20 may be adapted to absorb at least a portion of the amount of fluid that may leak from the self-containing cryogenic tank 12. The absorbing capacity may for instance be obtained by providing spaces between panels of the second thermally insulating layer 20.
Only a portion of the impermeable layer 16 may form the drip tray 18, e.g. the drip tray base portion 18′ and the drip tray rim portion 18″ in the
Furthermore, as a non-limiting example, the impermeable layer 16 may comprise a SUS membrane. Purely by way of example, the impermeable layer 16 may have a thickness within the range of 1-5 mm, preferably within the range of 2-3 mm.
The impermeable layer 16 layer may comprise a plurality of panels that are attached to one another, e.g. by means of weld joints. Optionally, the impermeable layer 16 may include one single panel. Purely by way of example, at least a portion of the impermeable layer 16 may be bent so as to assume the shape of the drip tray 18.
In the
It is envisaged that embodiments of the support assembly 10 may comprise a second layer 20 which is not, or at least not primarily, thermally insulating. In such an embodiment of a support assembly 10, the second layer 20 may instead be designed with a focus on providing a tank support function.
Moreover,
Purely by way of example, at least two of the thermally first or second insulating panels 14′, 14″, 20A′, 20A″, 20B′, 20B″ may be arranged such that a gap is obtained between the two panels. As a non-limiting example, the gap main be a void such that air is present in the gap.
Purely by way of example, the spacer means 22 comprises a wood panel, preferably a plywood panel. Moreover,
Preferably, at least one, but preferably the majority, of the thermally insulating panels comprises a glass fibre reinforced polyurethane foam. In the embodiment illustrated in
Irrespective of which material that is used, as a non-limiting example, a thermally insulating panel 14′, 14″, 20A′, 20A″, 20B′, 20B″, when arranged in the support assembly 10, may preferably have a compressive strength in the vertical direction V of at least 2 MPa, preferably at least 5 MPa, more preferred at least 7 MPa. Moreover, as a non-limiting example, a thermally insulating panel 14′, 14″, 20A′, 20A″, 20B′, 20B″ may have a compressive modulus in the vertical direction V of at least 100 MPa, preferably at least 140 MPa, more preferred at least 160 MPa. Furthermore, although purely by way of example, the thermal conductivity coefficient of the material of a thermally insulating panel may preferably be less than 1 W/mK, preferably less than 0.5 W/mK, more preferred less than 0.1 W/mK. A thermally insulating panel may be referred to as a slab.
As a non-limiting example, the thermal insulation around a tank 12, e.g. the insulation of the walls and/or the roof of an insulating structure surrounding the tank 12, may comprise, or alternatively consist of, one or more of the following materials: expanded polystyrene foam and polyurethane foam. Non-limiting examples for each one of the two different materials are presented in Tables 1 to 2 hereinbelow.
Moreover, as a non-limiting example, one or more of the thermally insulating panels may comprise, or alternatively consist of glass fiber reinforced polyurethane foam. Non-limiting examples for glass fiber reinforced polyurethane foam are presented in Table 3 hereinbelow. It is also envisaged that the glass fiber reinforced polyurethane foam may also, or instead, be used for thermal insulation of the walls and/or the roof surrounding a tank 12.
Moreover,
Additionally, the
Furthermore,
The support assembly 10 preferably comprises a leak drain conduit assembly 34 at least partially extending through the impermeable layer 16. The support assembly may also comprise a leak drain collector means 35, such as a leak drain collector container, adapted to be in fluid communication with the leak drain conduit assembly 34. As such, should a tank leakage occur, tank leakage fluid could be collected by the drip tray 18 and thereafter conducted to the leak drain collector means 35 via the leak drain conduit assembly 34. The leaked fluid may for instance subsequently be guided to a temporary or permanent leak drain connector tank (not shown).
As a non-limiting example, the size and position of the thermally insulating panels 20A′, 20A″, 20B′, 20B″ and the spacer means 22 may be selected such that the joints 18c are located between adjacent thermally insulating panels 20A′, 20A″, 20B′, 20B″.
The grooves 32′, 32″ may have the advantage that fluid that may leak from the tank onto the load distribution means 32 will be guided towards the periphery thereof via the grooves. The leaked fluid may then communicate with leakage sensors (such sensors are presented hereinbelow with reference to
As may be gleaned from
Purely by way of example, the first protrusion type 44 may have a horizontal strength that is larger than the horizontal strength of the second protrusion type 46.
During e.g. a thermal expansion or a thermal compression, the longitudinal end portions of the tank (not shown in
The non-zero vertical gap ΔV in each one of the
As a non-limiting example, and as may be gleaned from e.g.
The attachment means 38 illustrated in
However, in preferred embodiments of the support assembly 10, at least some, though preferably all, of the attachment means 38 are located within the support assembly 10.
To this end, reference is made to
As may be gleaned from
The first and second foundation portions 52, 54 are preferably made of a thermally insulating material. Purely by way of example, at least one of the first and second foundation portions 52, 54 is made of wood, preferably hard wood.
The first foundation portion 52 may preferably be attached to the second foundation portion 54 via the impermeable layer 16. In the
The foundation 50 may preferably also comprise a first connection panel 58 adapted to be located between the first foundation portion 52 and the impermeable layer 16. Moreover, the foundation may preferably also comprise a second connection panel 60 adapted to be located between the second foundation portion 54 and the attachment means 38. Preferably, the attachment means 38 is attached to the second connection panel 60 by means of a joint, such as a weld joint 62.
The first and second connection panel 58, 60 are preferably made of a relatively strong material. Purely by way of example, at least one of the first and second connection panel 58, 60 is made of metal, preferably steel.
Moreover,
In embodiments of the support assembly 10 that comprises a frame 26, such as the
In order to further reduce the risk of obtaining a thermal bridge between the attachment means 38 and the frame 26, at least one of the first and second bolt joints 56, 64 may preferably comprise thermally insulating washers (not shown in
Purely by way of example, the containment assembly 66 may be self-containing. As such, the containment assembly 66 does not necessarily have to be integrated in the structure in which it is adapted to be located. As a non-limiting example, the containment assembly 66 may be adapted to be moved in relation to the structure in which it is adapted to be located, for instance by a lifting assembly such as a crane (not shown) or the like.
The tank cover 68 is adapted to be connected to the support assembly 10 to thereby define a closed volume 69 adapted to accommodate the cryogenic tank 12. Preferably, the tank cover 68 is thermally insulating. Purely by way of example, the tank cover 68 may comprise panels of a thermally insulating material. As a non-limiting example, the thermally insulating material may be glass fibre reinforced polyurethane and/or polystyrene foam.
The containment assembly 66 may preferably comprise sealing means 70 adapted to provide a seal between the support assembly 10 and the tank cover 68. In the
Furthermore, the containment assembly 66 may comprise a gas source 84 in fluid communication with the closed volume 69 of the containment assembly 66. Purely by way of example, the gas source 84 may be used for purging a fluid, such a nitrogen, and possibly also trace substances into the closed volume 69. The fluid leaving the closed volume 69, for instance through the leak drain conduit assembly, may be analyzed in order to evaluate e.g. the function of the second thermally insulating layer 20.
A tank assembly 86 may preferably comprise a self-containing cryogenic tank 12 and a support assembly 10 of the present invention. As a non-limiting example, a tank assembly may comprise a self-containing cryogenic tank 12 and a containment assembly 66.
As such,
Preferably, a containment assembly 66 comprises the tank leakage test assembly 90 in addition to the tray leakage test assembly 78 that have been discussed in conjunction with
In the implementation of the tray leakage test assembly 90 illustrated in
The tray leakage test assembly 90 may preferably further comprise an electronic control unit 94 adapted to receive values indicative of the temperature in the vicinity of each one of the temperature sensors 92. Purely by way of example, a value indicative of a temperature may relate to at least one of the following entities: an actual temperature, a temperature change or a temperature change rate. Naturally, a value indicative of a temperature may comprise any combination of the above three entities.
Preferably, the tray leakage test assembly 90 further comprises a tray leakage test fluid source 96. Purely by way of example, the tray leakage test fluid source 96 may comprise a tank. The tray leakage test fluid source 96 may preferably be different from the above discussed gas source 84 that could possibly form a part of the above discussed tank leakage test assembly 78. Moreover, the tray leakage test fluid source 96 is preferably not the self-containing cryogenic tank 12 as such. Preferably, the tray leakage test fluid source 96 is separate from the self-containing cryogenic tank 12. The tray leakage test fluid source 96 may for instance be permanently installed in the support assembly 10. Optionally, the tray leakage test fluid source 96 is a separate and mobile unit that is also arranged by the support assembly 10 when the method for evaluating the tightness of a drip tray, as will be presented hereinbelow, is about to be carried out.
What is presented below is a method for evaluating the tightness of a drip tray 18 of a support assembly 10 for a self-containing cryogenic tank 12. In order to be able to perform the test method, the support assembly 10 preferably comprises a first thermally insulating layer 14 and an impermeable layer 16 located at least partially above the first thermally insulating layer 14. Moreover, the support assembly 10 comprises a plurality of temperature sensors 92 each one of which being located outside the impermeable layer 16 such that at least a portion of the first thermally insulating layer 14 is located between the sensor 92 and the impermeable layer 16. Moreover, the impermeable layer 16 at least partially forms the drip tray 18.
The method comprises introducing a fluid into the drip tray 18. The fluid may preferably be supplied from the tray leakage test fluid source 96. The fluid thus introduced has a temperature that is different from the temperature of the environment ambient of the support assembly. Purely by way of example, the fluid has a temperature that is above the temperature of the ambient environment.
However, in a preferred implementation of the test method, the fluid has a temperature that is lower than the temperature of the ambient environment. As a non-limiting example, the introduced fluid may be liquid nitrogen.
The drip tray method tightness evaluation method further comprises determining a value indicative of the temperature in the vicinity of each one of the temperature sensors. The value indicative of the temperature may for instance be one, or a combination of at least two, of the following entities: an actual temperature, a temperature change or a temperature change rate.
If no leakage occurs in the drip tray 18, the fluid introduced into the drip tray 18 will remain therein. Since the impermeable layer 16 does not generally have a large thermally insulating capability, the temperature of the impermeable layer 16 will assume a temperature that is relatively close to the temperature of the fluid. As such, if the temperature sensors 92 were to be placed in contact with the impermeable layer 16, the sensors 92 would most probably provide a temperature result in a more or less direct response to the temperature of the fluid.
However, according to the drip tray method tightness evaluation method of the present invention, each one of temperature sensors 92 is located outside the impermeable layer 16 such that at least a portion of the first thermally insulating layer 14 is located between the sensor 92 and the impermeable layer 16. As such, in the above discussed scenario where no leakage occurs, the temperature sensors 92 may detect a temperature that is different from the temperature of the fluid. Alternatively, the temperature sensors 92 may provide information indicative of that a relatively small temperature change has occurred. As another option, the temperature sensors 92 may provide information as regards a relatively low temperature change rate.
The magnitude of the either one of the above discussed temperature indication entities may for instance depend on at least one of the following: the initial temperature difference between the fluid and the ambient environment, the thermal insulation capacity of the first thermally insulating layer 14 and the amount of fluid introduced into the tray 18.
Any one of the above entities may preferably be predetermined, for instance by performing one or more test procedures for a non-leaking tray or by performing a heat conduction analysis.
Should there be one or more leakages in the drip tray 18, the fluid could pass therethrough to the first thermally insulating layer 14 during a test procedure. In such a scenario, the temperature sensor or sensors 92 located close to the leakage could then detect a temperature that is relatively close to the temperature of the fluid. Alternatively, the temperature sensors 92 may provide information indicative of that a relatively large temperature change has occurred at the temperature sensors 92 close to the leakage. As another option, the temperature sensors 92 may provide information as regards a relatively large temperature change rate at the temperature sensors 92 close to the leakage.
Any one of the above entities may also preferably be predetermined, for instance by performing one or more test procedures for a non-leaking tray or by performing a heat conduction analysis.
Three embodiments of the above discussed drip tray method tightness evaluation method will be presented hereinbelow.
In the first embodiment of the drip tray method tightness evaluation method, the value indicative of the temperature comprises a temperature in the vicinity of each one of the temperature sensors 92. The method comprises that the temperature determined at each temperature sensor 92 may be compared to a predetermined temperature range in order to determine whether or not the tightness of the drip tray 18 is impaired. As has been intimated hereinabove the end points of the predetermined temperature range may be established by means of test procedures and/or theoretical analyses.
The first embodiment of the drip tray method tightness evaluation method may also comprise that the above discussed comparison between the temperature determined at each temperature sensor 92 and the predetermined temperature range may be performed when a specific amount of time has elapsed from the time instant when the fluid was introduced into the drip tray 18. Such a predetermined temperature range may be an open or closed range. As such, if the fluid has a lower temperature than the ambient environment, the predetermined temperature range may include any temperature that is equal to or lower a predetermined threshold temperature.
As a non-limiting example, the first embodiment of the drip tray method tightness evaluation method may comprise that the temperature at each one of the temperature sensor 92 is determined when e.g. two minutes have elapsed from the time instant at which the fluid was introduced into the drip tray 18. If any one of the temperature sensor 92 then indicates a temperature that is within a specific temperature range (e.g. lower than 20° C. above the temperature of the fluid), this may be an indication that the drip tray 18 has a leakage.
In the second embodiment of the drip tray method tightness evaluation method, the value indicative of the temperature comprises a temperature change rate in the vicinity of each one of the temperature sensors 92. The method comprises that the temperature determined at each temperature sensor 92 may be compared to a predetermined temperature change rate range in order to determine whether or not the tightness of the drip tray 18 is impaired. As has been intimated hereinabove the end points of the predetermined temperature change range may be established by means of test procedures and/or theoretical analyses.
In the third embodiment of the drip tray method tightness evaluation method, the value indicative of the temperature in the vicinity of each one of the temperature sensors 92 is not necessarily compared to a predetermined range. Instead, in the third embodiment of the drip tray method tightness evaluation method may comprise that the values indicative of the temperature at each individual sensor are compared to one another in order to evaluate whether or not there is a large relative difference in the values. A large relative value difference may be indicative of a leakage. In a non-limiting example wherein the temperature as such is used as the above discussed value, the third embodiment may comprise that the temperatures in the vicinity of each one of the temperature sensors 92 are compared to one another. If a large temperature difference is detected between two temperature sensors 92, this may be an indication of a drip tray leakage. Purely by way of example, a temperature difference exceeding a predetermined difference threshold may be a value indicative of a large temperature difference between two temperature sensors 92.
It is also envisaged that further embodiments of the drip tray method tightness evaluation method may be obtained by combining two or three of the above discussed embodiments.
Furthermore, another non-limiting example of a value indicative of the temperature comprises a temperature change acceleration (i.e. a time derivative of the temperature change rate) at each one of the temperature sensors 92. The temperature change acceleration may be used instead of, or in addition to, at least one of the above discussed values indicative of the temperature.
Irrespective of which parameters that are used for the drip tray method tightness evaluation method, the method may preferably also comprise a step of indicating the position of the possible leakage. As a non-limiting example, the method may comprise a step of determining which one(s) of the temperature sensors that presents a value indicative of a leakage.
As a non-limiting example, the tray leakage test assembly 90 may preferably comprise a display 98, connected to the electronic control unit 94, which is adapted to present an illustration representative of the position of the temperature sensors. Purely by way of example, if the temperature sensors 92 are arranged so as to form a grid structure such as the one illustrated in
The drip tray method tightness evaluation method may further comprise that a signal is issued to the display 98, for instance from the electronic control unit 94, which signal comprises information as regards which sensor(s) that has determined a value indicative of a leakage. The display 98 may then highlight the leakage indicative sensors in the sensor grid, for instance by presenting such sensors in another colour as compared to the other sensors and/or to provide additional visual information close to such sensors.
Purely by way of example, the temperature change rate may be the maximum temperature change rate that occurred during a specific time range after the fluid has been introduced into the drip tray 18. As another alternative, the temperature change rate may be an average temperature change rate that occurred during a specific time range after the fluid has been introduced into the drip tray 18.
Instead of, or in addition to the drip tray method tightness evaluation method that has been discussed hereinabove, the tightness of the drip tray 18 may be evaluated by applying a negative pressure to an enclosed volume of the support assembly 10 in which the first thermally insulating layer 14 is located and evaluating the resulting negative pressure in the enclosed volume. As a non-limiting example, the negative pressure may be applied during a desired time interval on a regular or required basis. As another non-limiting example, the negative pressure may be applied constantly.
Finally, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. For instance, although embodiments of the present invention have been presented in relation to a vessel, such as a ship, hereinabove, it is envisaged that embodiments of the present invention also and/or instead could be used in and/or with land based structures. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
Number | Date | Country | Kind |
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20121338 | Nov 2012 | NO | national |
20121344 | Nov 2012 | NO | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2013/073701 | 11/13/2013 | WO | 00 |
Number | Date | Country | |
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61725516 | Nov 2012 | US |