Patent Application
20240426387
This disclosure generally relates to cryogenic fluids and, more particularly, to excess flow valves for cryogenic fluid tanks.
Cryogenic fluids, such as liquid hydrogen, has been used as fuel for machines, such as vehicles. Oftentimes, the cryogenic fluid is initially stored in a storage tank of a filling station. The cryogenic fluid is then transferred from the storage tank of the filling station to a fill tank of a vehicle for subsequent use as fuel for the machine. For instance, the filling station may include a nozzle that is connected to a hose extending from and fluidly connected to the storage tank of the filling station. A corresponding receptacle may be connected to the fill tank of the vehicle. To complete a filling sequence, an operator connects the nozzle to the receptacle. The cryogenic fluid subsequently flows from the storage tank of the filling station and into the fill tank of the vehicle.
In some instances, cryogenic fluid may flow too quickly through the filling station, thereby potentially resulting in spillage of cryogenic fluid from the filling station and/or damage to the filling station. To deter such an event from occurring, filling stations may implement an excess flow valve designed to limit the flow rate of cryogenic fluid to a predefined threshold. Further, an excess flow valve may be implemented on an engine fuel supply line of an engine that uses the cryogenic fluid as fuel to deter a spillage event during the operation of the engine. However, some excess flow valves may become less effective over time with repeated use.
An example excess flow valve disclosed herein for cryogenic fluid includes a valve body. The valve body includes an inner body surface that defines an inlet, an outlet, and a chamber extending between the inlet and the outlet. The valve body also includes a valve seat adjacent the outlet. The example excess flow valve also includes a piston plug disposed within the chamber and configured to slide axially between an open position and a closed position. The piston plug includes an inlet end positioned toward the inlet of the valve body, an outlet end positioned toward the outlet of the valve body, a plug at the outlet end configured to engage the valve seat in the closed position and be disengaged from the valve seat in the open position, an inner piston surface defining at least a portion of a fluid flow path for the cryogenic fluid between the inlet and the outlet, an outer piston surface, and an outer flange extending radially outward from the outer piston surface at the inlet end. The outer flange defines a flange surface. The outer flange, the outer piston surface, and the inner body surface at least partially define a spring slot that is outside of the fluid flow path. The example excess flow valve also includes a spring disposed in the spring slot. The spring includes a first end that engages the flange surface to bias the piston plug toward the open position.
In some examples, the valve body includes an inner ledge extending into the chamber between the inlet and the outlet. In some such examples, the inner ledge partially defines the spring slot and defines a fixed surface that engages a second end of the spring. Some such examples further comprise a guide adjacent the inner ledge. The guide includes a side surface that engages the inner ledge and a fixed surface that partially defines the spring slot and engages a second end of the spring. Further, in some such examples, the guide further includes an outer guide surface that engages the inner body surface of the valve body and an inner guide surface that engages the outer piston surface of the piston plug.
In some examples, the piston plug defines one or more holes that define a portion of the fluid flow path between the inlet and the outlet. The one or more holes are located adjacent the plug such that the one or more holes are axially positioned between the spring slot and the valve seat in both the open position and the closed position to direct the cryogenic fluid around the spring in both the open position and the closed position.
In some examples, the plug is configured to be disengaged from the valve seat in the open position when the spring is in an extended state, and the plug is configured to engage the valve seat in the closed position when the spring is in a compressed state.
In some examples, the piston plug is configured to slide axially toward the valve seat when a flow rate of the cryogenic fluid exceeds a predefined threshold flow rate that corresponds with a biasing force of the spring. In some such examples, the outer flange is configured to compress the spring as the piston plug slides axially toward the valve seat.
In some examples, the plug of the piston plug defines a bleed hole that fluidly connects the inlet to the outlet when the piston plug is in the closed position to subsequently facilitate the piston plug in returning to the open position by equalizing pressure between the chamber to the outlet.
In some examples, the inlet is configured to receive and fluidly connect to a first pipe, and the outlet is configured to receive and fluidly connect to a second pipe.
In some examples, the inlet has a diameter greater than that of the piston plug and the spring to enable the piston plug and the spring to be inserted into the chamber through the inlet. The valve seat has a diameter less than that of the piston plug and the spring to prevent the piston plug and the spring from being removed from the chamber through the outlet.
Some examples further comprise a retainer ring securely positioned within the chamber adjacent the inlet to retain the piston plug and the spring in place within the chamber. In some such examples, the inner body surface of the valve body defines a circumferential groove configured to receive the retainer ring. In some such examples, the outer flange of the piston plug is configured to rest against the retainer ring in the open position.
The description that follows describes, illustrates and exemplifies one or more embodiments of the present invention in accordance with its principles. This description is not provided to limit the invention to the embodiments described herein, but rather to explain and teach the principles of the invention in order to enable one of ordinary skill in the art to understand these principles and, with that understanding, be able to apply them to practice not only the embodiments described herein, but also other embodiments that may come to mind in accordance with these principles. The present specification is intended to be taken as a whole and interpreted in accordance with the principles of the present invention as taught herein and understood by one of ordinary skill in the art.
The scope of the present invention is intended to cover all such embodiments that may fall within the scope of the appended claims, either literally or under the doctrine of equivalents. The specification describes exemplary embodiments which are not intended to limit the claims or the claimed inventions. Features described in the specification, but not recited in the claims, are not intended to limit the claims.
It should be noted that in the description and drawings, like or substantially similar elements may be labeled with the same reference numerals. However, sometimes these elements may be labeled with differing numbers, such as, for example, in cases where such labeling facilitates a more clear description. Additionally, the drawings set forth herein are not necessarily drawn to scale, and in some instances proportions may have been exaggerated to more clearly depict certain features. Such labeling and drawing practices do not necessarily implicate an underlying substantive purpose.
Some features may be described using relative terms such as top, bottom, vertical, rightward, leftward, etc. It should be appreciated that such relative terms are only for reference with respect to the appended drawings. These relative terms are not meant to limit the disclosed embodiments.
Excess flow valves disclosed herein are configured to prevent an excess amount of cryogenic fluid, such as liquid hydrogen, from flowing through an engine fuel supply line and/or a filling station at any given time. The excess flow valve is configured to be open when the flow rate of cryogenic fluid flowing through the excess flow valve is less than or equal to a predetermined threshold flow rate. The excess flow valve is configured to be closed when the flow rate of the cryogenic fluid exceeds the predetermined threshold flow rate (e.g., resulting from a line breakage) to prevent the cryogenic fluid from potentially spilling from the engine fuel supply line and/or the filling station due to the heightened flow rate. Once the flow rate of the cryogenic fluid returns to be less than or equal to the predetermined threshold, the excess flow rate is configured to return to the open position to again permit the cryogenic fluid to flow.
Example excess flow valves disclosed herein include a body, a piston plug, and a spring. The body includes an inner body surface that defines a chamber, an inlet, an outlet, and a valve seat. The piston plug is configured to slide axially within the chamber between an open position and a closed position. The piston plug includes a plug at a first end that is configured to engage the valve seat in the closed position and be disengaged from the valve seat in the open position. The piston plug also includes an inner piston surface that defines at least a portion of a fluid flow path for the cryogenic fluid through the excess flow valve. The spring is configured to bias the piston plug to be disengaged from the valve seat in the open position.
In one embodiment, the piston plug also includes an outer piston surface opposite the inner piston surface and an outer flange that extends radially outward from the outer piston surface at a second end opposite the first end. The outer flange of the piston plug, the outer piston surface of the piston plug, and the inner body surface of the body at least partially define a spring slot for the spring that is outside of the fluid flow path. That is, the fluid flow path extends through an interior of the piston plug and the spring slot extends circumferentially around an exterior of the piston plug such that the piston plug fluidly isolates and spaces apart the spring slot from the fluid flow path. Further, the outer flange defines a spring surface that engages an end of the spring. The spring presses against the flange surface to bias the piston plug in a direction toward the open position. By being positioned within the spring slot that is spaced apart and fluidly isolated from the fluid flow path, the spring is not directly exposed to excessive flow rates of the cryogenic fluid that may otherwise deform the spring over time. In turn, the configuration of the spring within the spring slot extends the life of the excess flow valve.
In another embodiment, the plug of the piston plug defines a bleed hole that keeps the inlet fluidly connected to the outlet when the piston plug is in the closed position. The bleed hole enables a relatively small amount of cryogenic fluid to flow through it when the piston plug is in the closed position. The bleed hole equalizes the pressure on the two opposing sides of the plug and, in turn, facilitates the plug in disengaging from the valve seat and returning to the open position once the flow rate decreases to be less than or equal to the predefined threshold. For example, if the excess flow rate is not the result of a line breakage and subsequently decreases over time, the bleed hole facilitates the plug in returning to the open position.
Other embodiments of the excess flow valve include a combination of the above-identified features. For example, an example excess flow valve disclosed herein includes a combination of the spring being housed outside of the fluid flow path and the bleed hole of the plug of the piston plug.
Turning to the figures,
As shown in
The valve body 200 includes a first lip 242 that extends radially adjacent the inlet 215 of the valve body 200. The first lip 242 defines a first pipe-receiving section 251 of the chamber 250 and a first pipe-receiving surface of the inner body surface 240 adjacent the inlet 215. As shown in
Returning to
Returning to
Returning to
The valve body 200 of the illustrated example also includes an inner ledge 244 that defines a side surface 245. The inner ledge 244 extends into the chamber 250 inwardly toward the longitudinal axis of the valve body 200. The inner ledge 244 is located axially between the groove 253 and the valve seat 246. A first inner section 255 of the chamber 250 extends between the circumferential groove and the inner ledge 244. A second inner section 257 adjacent the first inner section 255 extends between the inner ledge 244 and the valve seat 246. As disclosed below in greater detail with respect to
Returning to
In the illustrated example, the piston plug 300 also defines a bleed hole 334. The bleed hole 334 extends between opposing sides of the plug 330 to keep the outlet 225 fluidly connected to the inlet 215 when the piston plug 300 is in the closed position. The bleed hole 334 has a relatively small diameter (e.g., about 0.5 millimeters) that enables the pressure on the two opposing sides of the plug 330 to equalize when the plug 330 is sealingly engaged to the valve seat 246. In turn, the bleed hole 334 facilitates the piston plug 300 in disengaging from the valve seat 246 and returning to the open position, for example, once a flow rate of the cryogenic fluid decreases to be less than or equal to a predefined threshold as disclosed below in greater detail. In the illustrated example, the bleed hole 334 is located at an apex of the plug 330. In other examples, the bleed hole 334 may be located at any other location on the plug 330 that fluidly connects the outlet 225 to the rest of the chamber 250 when the piston plug 300 is in the closed position. Further, in other examples, the plug 330 may define a plurality of bleed holes and/or one or more bleed slots to equalized the pressure within the chamber 250 when the piston plug 300 is in the closed position.
As shown in
As illustrated in
A spring slot 256 that houses the spring 400 is formed within the chamber 250. The spring slot 256 is a circumferential slot that extends circumferentially around a portion of the outer piston surface 352 of the piston plug such that the spring slot 256 is located along an outer radial portion of the first inner section 255 of the chamber 250. The spring slot 256 is at least partially defined by the flange surface 342 of the outer flange 340 of the piston plug 300, the outer piston surface 352 of the piston plug 300, and the inner body surface 240 of the valve body 200.
In the illustrated example, the spring slot 256 is defined by the flange surface 342, the outer piston surface 352, the inner body surface 240, and the side surface 640 of the guide 600. A first end of the spring 400 engages the flange surface 342 of the piston plug 300, and a second end of the spring 400 engages the side surface 640 of the guide 600. That is, the side surface 640 of the guide 600 partially defines the spring slot 256. The spring 400 presses against the side surface 640 to secure the guide 600 in place against the inner ledge 244 of the valve body 200 such that the second end of the spring 400 and the guide 600 are stationary during operation of the excess flow valve 100. The spring 400 presses against the outer flange 340 to bias the piston plug 300 in an open position. As disclosed below in greater detail, the piston plug 300 and, in turn, the outer flange 340 of the piston plug 300 is configured to slide axially along the longitudinal axis of the valve body 200 between the closed and open positions in a manner that compresses and expands the spring 400, respectively.
In another example, the excess flow valve 100 does not include the guide 600 with the spring slot 256 being defined by the flange surface 342, the outer piston surface 352, the inner body surface 240, and the side surface 245 of the valve body 200. That is, the inner ledge 244 partially defines the spring slot 256. The first end of the spring 400 engages the flange surface 342 of the piston plug 300, and the second end of the spring 400 engages the side surface 245 (also referred to as a “fixed surface” or a “fixed spring surface”) of the inner ledge 244. The spring 400 presses against the side surface 245 of the inner ledge 244 and is configured to remain stationary during operation of the excess flow valve 100. The spring 400 presses against the outer flange 340 to bias the piston plug 300 in the open position.
In
In operation, the spring 400 biases the piston plug 300 in the open position. The spring applies a biasing force to the outer flange 340 of the piston plug 300 in a direction toward the inlet 215. The biasing force of the spring 400 corresponds with a threshold flow rate of cryogenic fluid for the excess flow valve 100. Cryogenic fluid flowing along the fluid flow path applies an opposing force to the piston plug 300 in a direction toward the outlet 225. The force applies by the cryogenic fluid corresponds with the flow rate of the cryogenic fluid. A greater flow rate corresponds with a greater force applied by the cryogenic fluid onto the piston plug 300, and a lesser flow rate corresponds with a lesser force applied by the cryogenic fluid onto the piston plug 300.
When a flow rate of the cryogenic fluid is less than or equal to the threshold flow rate, the spring 400 pushes the piston plug 300 to the open position. That is, the spring 400 is in an extended state and pushes the outer flange 340 of the piston plug 300 to rest against the retainer ring 500 securely positioned within the groove 253 of the valve body 200. In turn, the plug 330 on the opposing side of the piston plug 300 is disengaged from the valve seat 246 to enable fluid to flow to and through the outlet 225 of the excess flow valve 100.
When the flow rate of the cryogenic fluid becomes greater than the threshold flow rate, the flow of the cryogenic fluid overcomes the biasing force of spring 400 and pushes the piston plug 300 to slide axially in a direction toward the valve seat 246 and the outlet 225. The outer flange 340 of the piston plug 300 is configured to compress the spring 400 into a compressed state as the piston plug 300 slides toward the valve seat 246. The plug 330 is configured to engage the valve seat 246 in the closed position when the spring is in the compressed state. The plug 330 engages the valve seat 246 in the closed position to prevent the cryogenic fluid from flowing through the excess flow valve 100 at elevated flow rates.
The excess flow valve 100 returns to the open position to again permit the cryogenic fluid to flow only after the flow rate of the cryogenic fluid returns to be less than or equal to the threshold flow rate. Once the flow rate becomes less than the threshold flow rate, the spring 400 pushes the piston plug back to the open position. In turn, the plug 330 disengages from the valve seat 246 to again permit cryogenic fluid to flow through the excess flow valve 100.
To assembly the excess flow assembly 10, the excess flow valve 100 is first assembled. The excess flow valve 100 is assembled by inserting the guide 600 and then the spring 400 through the inlet 215 and into the first inner section 255 of the chamber 250 of the valve body 200. The piston plug 300 is then inserted through the inlet 215 and into the first inner section 255 and the second inner section 257 of the chamber 250. The piston plug 300 is inserted into the chamber 250 such that the piston plug 300 extends through the spring 400 and the guide 600. Each of the inlet 215, the first pipe-receiving section 251, the groove 253, and the first inner section 255 has a respective diameter greater than those of the piston plug 300, the spring 400, and the guide 600 to enable the piston plug 300, the spring 400, and the guide 600 to be inserted into the first inner section 255 of the chamber 250 via the inlet 215. Additionally the valve seat 246 has a diameter less than those of the piston plug 300, the spring 400, and the guide 600 to prevent the piston plug 300, the spring 400, and the guide 600 from being remove from the chamber 250 via the outlet 225. Subsequently, the retainer ring 500 is inserted through the inlet 215 and securely positioned within the groove 253 of the chamber 250. The retainer ring 500 is flexible to enable the retainer ring 500 to flex inwardly as the retainer ring 500 is inserted into the chamber 250 and to snap back to a rest state once the retainer ring 500 is positioned within the groove 253. The retainer ring 500 is positioned within the groove 253 adjacent the inlet 215 to securely the piston plug 300, the spring 400, and the guide 600 in place within the chamber 250 of the valve body 200. Once the excess flow valve 100 is assembled, the pipe 700 is secured to the inlet 215 via the weld 750 and the pipe 800 is secured to the outlet 225 via the weld 850 to complete the assembly of the excess flow assembly 10.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2021/115338 | 8/30/2021 | WO |
