Interrogation of temperature sensitive coatings on fuel tank exterior

Abstract

Disclosed is a system for controlling gaseous hydrogen (GH.sub.2) refueling of a GH.sub.2 vehicle, wherein a vehicle fuel tank is refilled with GH.sub.2 from an external supply tank. The system includes a target patch or a cell of a temperature-dependent reflectivity material on an exterior of the vehicle fuel tank, and a sensor package including an electromagnetic (EM) radiation emitter and a radiation detection system positioned remote from the vehicle tank being filled. The sensor package is located on or adjacent an external refueling device with a line of sight to the target patch or cell.

Claims

1. A system for controlling gaseous hydrogen (GH.sub.2) refueling of a GH.sub.2 vehicle, wherein a vehicle fuel tank is refilled with GH.sub.2 from an external supply tank, said system comprising an unpowered temperature sensor comprising a patch or a cell of a temperature-dependent reflectivity material on an exterior of the vehicle fuel tank, and a sensor package comprising an electromagnetic radiation emitting system and a radiation detection system positioned remote from the vehicle tank being filled, wherein the sensor package is located on or adjacent an external refueling device with a line of sight to the unpowered temperature sensor patch or cell.

2. The system of claim 1, wherein the radiation emitting system, and the radiation detection system is configured to emit and detect radiofrequency (RF) radiation, infrared radiation (IR) or electromagnetic (EM) radiation.

3. The system of claim 1, wherein the temperature-dependent reflectivity material comprises a thermochromic material or a mechanochromic material.

4. The system of claim 1, wherein the temperature-dependent reflectivity coating material exhibits reflective changes at temperatures between 0 C. and 65 C.

5. The system of claim 1, further comprising a controller configured to control delivery of said GH.sub.2 in response to detected changes in reflection of said temperature-dependent reflectivity material.

6. The system of claim 1, wherein the vehicle comprises a motor vehicle or an aircraft.

7. The system of claim 1, wherein the temperature-dependent reflectivity material is applied to a plurality of unpowered temperature sensor patches or cells.

8. The system of claim 7, wherein the temperature-dependent reflectivity material applied to individual unpowered temperature sensor patches or cells of said plurality of unpowered temperature sensor patches or cells have different transition temperatures.

9. An article of manufacture comprising computer readable storage medium storing instructions to cause gaseous hydrogen (GH.sub.2) refueling system for a vehicle to: collect data regarding a surface temperature of a fuel tank carried by the vehicle by remotely interrogating the fuel tank using the system of claim 1; compare said data to a target temperature; and controlling delivery of GH.sub.2 to the vehicle on the comparison.

10. The article of manufacture of claim 9, the vehicle comprises a motor vehicle or an aircraft.

11. A method for controlling refueling of a hydrogen (H.sub.2) fuel-cell-powered vehicle, said vehicle having a fuel tank configured to hold a quantity of compressed GH.sub.2 from an external filling device, said method comprising providing on an exterior of the vehicle fuel tank an unpowered temperature sensor comprising a patch or cell of a temperature-dependent reflectivity material, interrogating the unpowered temperature sensor patch or cell with a radiation emitting system and radiation detector system positioned remote from the vehicle tank with a line of sight to the unpowered temperature sensor, and controlling delivery of said GH.sub.2 in response to detected changes in reflection of said temperature-dependent reflectivity material.

12. The method of claim 11, wherein the temperature-dependent reflectivity material comprises a thermochromic material or a mechanochromic material.

13. The method of claim 11, wherein the temperature-dependent reflectivity material is applied as a plurality of unpowered temperature sensor patches or cells.

14. The method of claim 13, wherein individual unpowered temperature sensor patches or cells of said plurality of unpowered temperature sensor patches or cells have different transition temperatures.

15. The method of claim 11, wherein the radiation emitting and radiation detecting system is configured to emit and detect RF radiation, IR radiation or electromagnetic (EM) radiation and including the step of directing said RF radiation, IR radiation or electromagnetic (EM) radiation at the unpowered temperature sensor and detecting a reflection of said radiation off said unpowered temperature sensor.

16. The method of claim 15, wherein the temperature-dependent reflectivity coating material exhibits a transition temperature between 0 C. and 65 C.

17. The method of claim 15 including a step of retarding a rate of refueling in the event a detected change in reflection of said temperature-dependent reflectivity material exceeds a target.

18. The method of claim 15 including a step of cutting off delivery of GH.sub.2 in the event a detected change in reflection of said temperature-dependent reflectivity material exceeds a target.

19. The method of claim 15 including a step of increasing a rate of refueling in the event a detected change in reflection of said temperature-dependent reflectivity material falls below a target.

20. The method of claim 15, wherein the vehicle is a motor vehicle or an aircraft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages of the disclosure will be seen in the following detailed description, taken in conjunction with the accompanying drawings. The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure.

(2) In the drawings:

(3) FIG. 1 schematically illustrates an aircraft GH.sub.2 refueling system in accordance with the present disclosure;

(4) FIG. 2 is a schematic view of a hydrogen FC-powered motor vehicle having fuel tanks with cells coated with thermochromic or mechanochromic material in accordance with the present disclosure;

(5) FIG. 3 is a schematic view of a hydrogen FC-powered aircraft having fuel tanks with cells coated with thermochromic or mechanochromic material in accordance with the present disclosure; and

(6) FIG. 4 is a flowchart illustrating a method of controlling refueling of an aircraft with GH.sub.2 in accordance with the present disclosure.

DETAILED DESCRIPTION

(7) Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth, such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

(8) The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms a, an, and the may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms comprises, comprising, including, and having are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

(9) When an element or layer is referred to as being on, engaged to, connected to, or coupled to another element or layer, it may be directly on, engaged, connected, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being directly on, directly engaged to, directly connected to, or directly coupled to another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., between versus directly between, adjacent versus directly adjacent, etc.). As used herein, the term and/or includes any and all combinations of one or more of the associated listed items.

(10) Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Terms such as first, second, and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the example embodiments.

(11) Spatially relative terms, such as inner, outer, beneath, below, lower, above, upper, and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as below or beneath other elements or features would then be oriented above the other elements or features. Thus, the example term below can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

(12) In FIG. 1, there is shown a refueling system 10 for refueling a GH.sub.2 tank 12 in accordance with the present disclosure. The GH.sub.2 tank 12 may be incorporated into a motor vehicle such as a truck as illustrated in FIG. 2, or in an aircraft as illustrated in FIG. 3. Tank 12 includes a closable inlet 13 configured to receive a filling nozzle 14 in a gas tight arrangement. Inlet 13 is a conventional inlet for GH.sub.2 tanks and will not be described further.

(13) Outer surface 16 of tank 12 is coated in part with a temperature-dependent reflectivity coating material, i.e., at 18. Temperature-dependent reflectivity coating material comprises a thermochromic material or mechanochromic material chosen to change reflectivity at a pre-determined temperature. In the case of a GH.sub.2 tank the predetermined temperature is 65 C. to allow a sufficient margin of safety relative to the 85 C. temperature limit typically imposed on Type IV hydrogen storage tanks. A suitable thermochromic material comprises a coating containing colloidal nanocrystals of tungsten doped vanadium dioxide. Such material is available from Nanochemazone, Inc. of Leduc, Alberta, Canada. Other useful thermochromic or mechanochromic materials useful in the present disclosure include cadmium sulfide.

(14) In a preferred embodiment, the outer surface 16 of tank 12 is coated with a plurality of patches or cells 18a, 18b, 18c of thermochromic material or mechanochromic material, each cell having a different transition temperature.

(15) The refueling station 20 comprises a refueling tank 22 which is connected via a dispenser and flow meter 24 via a conduit 26 to nozzle 14. Refueling station 20 also includes a light source 28 configured to emit EM interrogating radiation of 2500 nm, and a detector 30 configured to detect radiation in the 2450-2550 range. Detector 30 is configured to detect reflection from thermochromic coating 18 and to trigger a signal to controller 32 when reflective light representative of a temperature of 65 C. is sensed. Controller 32 controls dispenser 24 and nozzle 14 to maintain a safe and efficient filling speed.

(16) Referring to FIG. 2 there is illustrated a motor vehicle 40 in accordance with the present disclosure. Motor vehicle 40 comprises a truck 42 powered by hydrogen fuel cells (not shown). Truck 42 includes GH.sub.2 fuel tanks 44, 46 which include patches 48, 50 of a thermochromic material coated on exterior walls of tanks 44, 46.

(17) Referring to FIG. 3 there is illustrated an aircraft 50 in accordance with the present disclosure. Aircraft 50 includes a fuselage 52, wings 54, 56, and fuel cells 58, 60 carried within wings 54, 56. GH.sub.2 fuel tanks 62, 64 are carried under wings 54, 56, and include patches 66, 68 on exterior surface of the tanks 62, 64 coated with a thermochromic material as above described. Optionally, aircraft 50 may include fuel tank shown in phantom at 70 carried within the fuselage 52. As in the case of tanks 62, 64 tank 70 should include one or a plurality of patches or cells coated with a thermochromic material or a mechanochromic material as above described. When tank 70 is carried within the fuselage, the fuselage should be provided with a trap door or window 72 which is transparent to the interrogating EM radiation and reflection from the thermochromic or mechanochromic material or the tank exterior.

(18) Referring to FIG. 4, a GH.sub.2 tank refueling system 100 is depicted as a block diagram illustrating various components and modules. The overall process is as follows:

(19) A filling hose is connected between a refueling tank and the vehicle at step 102. Thereafter, a light source is activated at step 104, directed to the coating surface on the tank being filled. A sensor is activated at step 106 and begins to transmit sensor data in step 108 to a controller 110. The GH.sub.2 dispenser is activated in step 112, the filling hose nozzle is opened in step 114, and filling is commenced.

(20) Filling continues until the sensor signals an instant temperature rise above 65 C. If an instant temperature exceeds a preset maximum, the controller activates to slow down or shut down the dispenser in step 112 and/or close or partially close nozzle in step 114. If the temperature sensed by the sensor is below a preset target temperature, the controller acts to gradually increase fuel flow by increasing the dispenser speed in step 112 and/or further opening the nozzle in step 114. Filling continues until the tank is full.

(21) The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. Various changes and advantages may be made in the above disclosure without departing from the spirit and scope thereof.