The present teachings generally relate to a connector for transporting fluid between a reservoir and a system. In particular, the present teachings relate to a system to reservoir connector for providing positive valve closure on both halves of the connector to minimize fluid loss.
Fuel cells are becoming a more important source of electrical energy for a variety of uses, including personal electronic devices, electric vehicles, and other electrically powered devices. Some liquid fuels can be used directly in direct oxidation fuel cells. When the fuel is methanol, the fuel cell is typically referred to as a direct methanol fuel cell (DMFC). A DMFC is the most suitable fuel cell for portable applications. It offers the users the opportunity to quickly replace an empty fuel cartridges with a full one. However, in conventional systems, the connectors used to connect a fuel cartridge to the fuel cell may leak during attachment and detachment from the fuel cell. Also, external forces may disrupt the fluid transport from the fuel cartridge causing a disruption or fluctuation in the power provided by the fuel cell. In addition, how much fuel can be transferred to the fuel cell is largely dependent on the orientation of the connector. In a less favorable orientation, a large amount of fuel will remain in the cartridge without being able to be transferred to the fuel cell.
Therefore what is needed is a connector that provides positive valve closures on both halves of the connector for minimizing fluid loss upon connect and disconnect, minimizes the effect of external forces on the fluid transport integrity, and is orientation independent.
System to reservoir connectors are disclosed. In one instance, a system to reservoir connector is provided in which a system-side-sub-connector and a reservoir-side-sub-connector provide for a fluid connection that is resilient to external forces and is substantially leak proof upon insertion and retraction and is orientation independent.
The system to reservoir connector includes first and second sub-connectors that are complementary to one another and allow for motion of each of the sub-connectors relative to the other. Each of the first and second sub-connectors includes a series of seals, fluid transfer components (a wick in one embodiment, these teachings not being limited to only that embodiment), and collapsible/extendable components (springs in one embodiment, these teachings not being limited to only that embodiment) that ensure positive fluid communication between the two sub-connectors and provide a substantially leak-proof connection.
Embodiments of the system to reservoir connector and methods for use thereof are disclosed.
Aspects of the present teachings are pointed out with particularity in the appended claims. The present teachings are illustrated by way of examples in the following drawings in which like references indicate similar elements (except for
a is a cross sectional view of one embodiment of the system (e.g., a fuel cell engine) side and the reservoir (e.g., fuel supply or cartridge) sealed together with both valves closed, corresponding to the embodiment of
b is a cross sectional view of one embodiment of the system side and the cartridge side sub-connectors sealed together with both valves open, corresponding to the embodiment of
a and 4b are cross-sectional views of both the system-side-sub-connector and the reservoir-side-sub-connector in another embodiment of the system of these teachings;
c is a cross-sectional view of both the system-side-sub-connector and the reservoir-side-sub-connector of
The following detailed description sets forth numerous specific details to provide a thorough understanding of the teachings. However, those skilled in the art will appreciate that the teachings may be practiced without these specific details. In other instances, well-known methods, procedures, components, protocols, processes, and circuits are not described in detail so as not to obscure the teachings.
Embodiments of a system to reservoir connector in accordance with the present teachings are described in more detail below. The system to reservoir connector includes a first and a second sub-connectors that are complementary to one another and allow for motion of the sub-connectors relative to each other. Each of the first and second sub-connectors includes a series of seals, fluid transfer components (a wick in one embodiment, but these teachings not being limited to only that embodiment) and collapsible/extendable components (springs in one embodiment, but these teachings not being limited to only that embodiment) that ensures positive fluid communication between the two sub-connectors and that provides for a substantially leak-proof connection.
In one embodiment, the system to reservoir connector of these teachings includes a system-side-sub-connector and a reservoir-side-sub-connector. The system-side-sub-connector has a system-side-housing, a fluid transfer component disposed in an interior portion of the system-side-housing and extending from a system end of the system-side-housing to a reservoir end of the system-side-housing, a first portion of the fluid transfer component having a first end proximate to the system end of the system-side-housing; the first portion extending from an exterior of the system end of the system-side-housing to an interior of the system-side-housing, a second portion of the fluid transfer component having a second end proximate to the reservoir end of the system-side-housing, the second portion being able to obtain fluid from the reservoir-side-sub-connector and to provide the obtained fluid to the first portion (being in fluid communication), a system side seal component capable of, in one configuration of the system-side-sub-connector, preventing fluid transfer in/out of the system, and an extendable/collapsible component. The system side seal component includes a first portion disposed substantially coaxially over a portion of the fluid transfer component and a second portion disposed over the second end of the fluid transfer component, the second seal component portion being attachable/detachable (forming a sealed/unsealed form) from the first seal component portion. The extendable/collapsible component is operatively connected to the first seal component portion and capable of enabling to seal/unseal (attachment/detachment) of the first and the second seal component portions; and also capable of retracting the first seal component portion into a second configuration, wherein the first seal component portion not being disposed when in the second configuration, over at least part of the portion of the fluid transfer component.
The reservoir-side-sub-connector can operate in an open configuration or in a closed configuration. The reservoir-side-sub-connector includes a reservoir-side-housing, a reservoir side fluid transfer component adapted to be, when in the open configuration, in fluid communication with the fluid transfer component in the system-side-sub-connector, and a reservoir side seal. In one instance, the reservoir side fluid transfer component is also partially enclosed in the reservoir. In another instance, the reservoir side fluid transfer component comprises the reservoir. Both of these instances are within the scope of these teachings. The reservoir side fluid transfer component is disposed inside the reservoir-side-housing, and has a first reservoir fluid transfer component portion extending from a reservoir side of the reservoir-side-housing to a location inside the reservoir-side-housing, and a second portion of the reservoir fluid transfer component. The second portion of reservoir side fluid transfer component is in fluid communication with the first portion of the reservoir side fluid transfer component. The reservoir side fluid transfer component has a first end proximate to the reservoir and a second end proximate to a system side of the reservoir-side-housing. In one instance, the reservoir side seal is capable of, in the closed configuration, substantially preventing fluid transfer from the second end of the reservoir side fluid transfer component. In one instance, the reservoir side seal component has at least a portion disposed over and operatively connected to another collapsible/extendable component, that portion being capable of being retracted and allowing, when in the open configuration, fluid communication between the reservoir side fluid transfer component and the fluid transfer component of the system-side-sub-connector.
The reservoir-side-housing is sized and dimensioned to have a portion, including the system end of the reservoir-side-housing that is received in the interior of the system-side-housing. In one embodiment, the reservoir-side-housing also has an opening at the system end, that being dimensioned to receive the second end of the fluid transfer component of the system-side-sub-connector, and also being dimensioned to receive the second seal component portion of the system-side-sub-connector. The reservoir-side-housing, in one embodiment, also has a channel extending from an opening at the system end of the reservoir-side-sub-connector to an opening into the interior of the reservoir-side-sub-connector. The channel is dimensioned to receive the second end of the fluid transfer component of the system-side-sub-connector. The channel is also dimensioned to receive the second seal component portion of the system-side-sub-connector.
In one instance, the portion of the reservoir-side-housing, including the system end of the reservoir-side-housing, when received in the system-side-housing, operatively connects with the first seal component portion of the system-side-sub-connector and breaks the seal between the first seal component portion and the second seal component portion. The second seal component portion enters into and moves along the channel in the reservoir-side-sub-connector. After the second seal component portion reaches the opening into the interior of the reservoir-side-housing, the second seal component portion operatively connects to the reservoir side seal component and breaks the seal of the reservoir side seal component to get into the interior of the reservoir-side-sub-connector. In one embodiment, the portion of the reservoir-side-housing that is received by the system-side-housing and the channel are dimensioned such that the two housings seal together first, then the seal between the first seal component portion and the second seal component portion of the system-side-housing is broken, and subsequently the seal of the reservoir side seal component opening into the interior of the reservoir-side-sub-connector is broken. One detailed embodiment is shown in
To allow the fluid to flow through the sub-connectors (and, in the instance where the sub-connectors are in open configuration, the complete connector), it is highly desirable to utilize a capillary flow process. The use of capillary flow process enables flow under almost any type of orientation. Capillary flow via a capillary tube (capillary conduit) is one method to establish this flow. Capillary tubes can be built into both sides of the connector and through capillary action provide continuous feed of fluid through the connector. In addition to capillary tubes, porous materials can be employed to provide capillary flow action through “wick” materials. A “wick,” as used herein, refers to a material of any porosity or permeability that can wick a fluid at a desired (predetermined) flow rate. In one embodiment, the “wick” comprises an absorbent material. Suitable absorbent materials include, but are not limited to, sponges, fibrous polymers such as polyester, polyethylene, polyolefin, polyacetal, and polypropylene, or natural fibers such as hemp, cotton, or cellulose acetate or other plant-based fibers. In one instance, when polymeric fibers are used, these fibers are either thermoset or thermoplastic with high enough softening and/or melting temperatures to withstand potentially high internal temperatures that may exist inside the system such as a fuel cell or inside electronic devices. Although the description hereinbelow concentrates on wick materials, the use of capillary tubes (conduits) is also considered part of the art of this application.
A wick transports a liquid such as fuel (methanol in one exemplary instance) mainly through capillary forces. While not desiring to be bound by theory, one explanation of capillary action is provided below. Capillary action occurs when the adhesive intermolecular forces between the liquid and the surface of a solid are stronger than the cohesive intermolecular forces within the liquid. The Young-Laplace equation states that the capillary pressure, PC, is proportional to the surface tension, γ, and cosine of the contact angle, θ, of the liquid on the surface of the capillary, and inversely proportional to the effective radius, r, of the meniscus formed at the interface, as shown below,
The fuel (methanol in the exemplary instance) flow in the wick materials is governed by the capillary force, viscous force, and gravity force. As known, methanol is a wetting liquid to most of the surfaces, or, the contact angle is less than 90° with most of the solid materials. Therefore, the capillary force of the methanol in the wick is the key driving force to make it flow, while overcoming the resistant forces, including viscous force and/or gravity. Since the capillary forces can be much stronger than the combined viscous and gravity forces when the diameter of the capillary is made small enough (such as 100 microns), liquid methanol can be wicked in any direction. In other words, the system is basically orientation independent.
Along the wicking flow direction, the methanol would be trying to move to the downstream pores, and then build up a new meniscus in the next available pores. If the next pores are larger, the available methanol will be difficult to build up the new meniscus inside, which leads to a smaller or even zero capillary force to drive the methanol to flow further. Therefore, it is desirable to make sure that the pore size does not get larger along the desired methanol wicking flow direction.
If a single wick is used, it is acceptable to have the pore size or the diameter of capillary tubes be the same along the liquid wicking flow direction. However, it would be preferable if the wick is designed such that the pore sizes or the diameter of capillary tubes decrease along the desired methanol flow direction. If two (or more) wicks are used to transport the liquid, such as the case described herein where there is a cartridge (reservoir) side wick and a system side wick, the pore size or the diameter of capillary tubes within the system side wick should not be larger than that within the cartridge side wick. Preferentially, the pore size or the diameter of capillary tubes within the system side wick is smaller than that within the cartridge side wick so that the methanol flow from the cartridge to the fuel cell system will be facilitated.
In the embodiment shown in
The reservoir (also referred to as the cartridge, although these teachings are not limited only to a cartridge) side 104 includes a reservoir (cartridge) side case 121 that includes an interior portion 121a, a system end 121b, and a reservoir (cartridge) end 121c. A channel 121d extends from the opening 121e in the system end 121b to an opening 121f in the interior portion 121a of the reservoir side case 121. A hollow piston 128 is coaxially disposed on the longitudinal axis of the cartridge side case 121. A portion of a cover seal 124 is disposed over a system side head 128a of the hollow piston 128. That portion of the cover seal 124 is dimensioned and arranged so that, in the closed configuration, that portion of the cover seal 124 seals the opening 121f into the interior portion 121a. In some embodiments, the hollow piston 128 comprises the cover seal 124 or the cover seal 124 comprises a hollow piston 128. A compression spring 130 is disposed within the hollow piston 128. The compression spring 130 is seated at cartridge spring seat 137 that is disposed against a wall 132 at the cartridge end 121c. A first wick 134 extends through the wall 132 and extends coaxially through the interior portion 121a. A second wick 136 is in fluid communication with first wick 134 and is also coaxially disposed within the interior 121a, but is closer to the longitudinal axis of the cartridge case 121
a depicts a cross sectional of the cartridge side 104 being inserted into the system side 102, for the embodiment shown in
Subsequently in the insertion, the system end 121b (
At a later stage in the insertion, the end seal 116 presses against the head 128a (
b depicts a cross sectional portion of the cartridge side 104 being engaged within system side 102 and allowing fluid communication between the two sides, for the embodiment shown in
Another embodiment of the system-to-reservoir connector of these teachings (also referred to as “the second embodiment”) is shown (in cross-sectional view) in
In one instance, during operation, especially, but not limited to, during multiple insertions, fluid can remain in the cartridge-side-sub-connector portion 104, a situation which may lead to unintentional or undesired leakage of fluid to the system-side-sub-connector during insertion. Embodiments of the cartridge-side-sub-connector portion 104 with components or features for allowing transfer of fluid from an interior portion (121a,
One embodiment of the method for operating the system-to-reservoir connector of these teachings, as described herein above, can be summarized as follows. A connector is provided that has a system-side-sub-connector and a reservoir-side-sub-connector. The system-side-sub-connector and the reservoir-side-sub-connector are initially closed. Each sub-connector has a seal component substantially preventing fluid from flowing out of the sub-connector when in a sealed configuration. The seal component in each sub-connector is capable of being unsealed/sealed and is sealed when the system-side-sub-connector and the reservoir-side-sub-connector are closed. A portion of the reservoir-side-sub-connector is inserted into the system-side-sub-connector while maintaining the seal components in a sealed configuration. First, the reservoir side-sub-connector seals to the system-side-sub-connector. Subsequently, insertion of the portion of the reservoir-side-sub-connector into the system-side-sub-connector continues, rendering the seal component in the system-side-sub-connector in a unsealed configuration, whereby fluid flow into the system-side-sub-connector is enabled. Finally, connecting the reservoir-side-sub-connector to the system-side-sub-connector is completed by completing the insertion, rendering the seal component in the reservoir-side-sub-connector in the unsealed configuration and placing a fluid transfer component in the reservoir-side-sub-connector in fluid communication with a fluid transfer component in the system-side-sub-connector, whereby fluid flow out of the reservoir-side-sub-connector is enabled when connecting a system to a reservoir, leakage of fluid can be substantially prevented by utilizing a system-to-reservoir connector of these teachings.
The corresponding embodiment of the method for closing the system-to-reservoir connector of these teachings is the reverse of the above described embodiment. A portion of the reservoir-side-sub-connector is retracted from the system-side-sub-connector, rendering the seal component in the reservoir-side-sub-connector in the sealed configuration, whereby fluid flow out of the reservoir-side-sub-connector is disabled. Subsequently, the reservoir-side-sub-connector is disengaged from the system-side-sub-connector, rendering the seal component in the system-side-sub-connector in a sealed configuration, whereby flow into the system-side-sub-connector is disabled. Finally, the system-side-sub-connector and reservoir-side-sub-connector are fully separated breaking the final seal between them.
It should be noted that similar systems utilizing flow transfer components other than wicks, different configurations of collapsible/extendable components, other than springs or exchanging compression and tension springs, are also within the scope of these teachings.
It should be noted that the connection between the system-side-sub-reservoir and the system and the connection between the reservoir-side-sub-connector and the reservoir are conventional.
It should be appreciated that other variations to and modifications of the above-described method and system for providing a system-to-reservoir connector may be made without departing from the inventive concepts described herein. Accordingly, the teachings should not be viewed as limited except by the scope and spirit of the appended claims.