Equipment and methods for cooling cryogenic pumps

Abstract

Equipment and methods for pumps used to cool liquid hydrogen or other cryogenic fluids can be configured to allow for rapid start-up, which also helps to minimize hydrogen loss. Some embodiments may utilize a leakage circuit configured and arranged to support cryogenic cooling operation of the pump, which can minimize hydrogen loss while allowing for significantly improved pump start-up time. Some embodiments may utilize at least one temperature sensor to monitor temperature, and an adjustable control valve that can facilitate the flow of fluid used to cool the pump.

Description

Technical Field

[0001] The present invention relates to apparatus and methods for cooling pumps that can be positioned and configured to use cryogenic fluids (e.g., liquid hydrogen, liquid oxygen, liquid nitrogen, liquid helium, etc.). Background Technology

[0002] Examples of hydrogen generation and supply systems can be understood through U.S. patent numbers 6,401,767, 6,474,078, 6,619,336, 6,708,573, 6,745,801, 6,786,245, 7,028,724, 7,328,726, 7,793,675, 7,921,883, 8,020,589, 8,286,675, 8,365,777, 8,453,682, 8,899,278, 9,074,730, 9,151,448, 9,261,238, 9,279,541, 9,404,620, 9,863,583, 10,502,649, and 10,508,770.

[0003] Some hydrogen refueling applications can utilize liquid hydrogen pumps. Examples of such pumps can be understood through U.S. Patent Application Publications 2007 / 0227614 and 2018 / 0058441, Chinese Patent Publications CN111765064A and CN110429300A, and Chinese Utility Model CN213116590U.

[0004] As disclosed in U.S. Patent No. 5,537,828, cryogenic pumps can cool cryogenic liquids to a suitable cryogenic temperature before they can be transferred from a low-pressure tank to a high-pressure tank, in order to help minimize liquid vaporization before the liquid reaches the pump. Cryogenic pumps typically do not work well in the presence of steam or even mixtures of liquid and steam.

[0005] One solution already used to address this problem is to immerse the pump in a cryogenic fluid to ensure it remains at liquid hydrogen temperature. For example, U.S. Patent No. 6,474,078 discloses this technique.

[0006] U.S. Patent Application Publication No. 2014 / 0096540 discloses a pump for conveying liquefied natural gas (LNG) from a distribution station. Cryogenic LNG needs to flow continuously through the pumping system to keep the pump components at a sufficiently low temperature to avoid cold shock or differential heating of the impeller. Summary of the Invention

[0007] We have identified a need for a new method and apparatus for cooling operations of cryogenic pumps to help minimize the loss of cryogenic fluids (e.g., hydrogen) while reducing the time required to start up the pump. Some embodiments may allow start-up times as short as two minutes or less, while significantly reducing hydrogen fuel loss (e.g., some embodiments may reduce hydrogen loss by more than 50%). In some embodiments, the pump may undergo a cooling operation performed prior to pump operation to help drive fluid flow to distributors, flow control manifolds, or other downstream units. Embodiments may be configured such that the cooling cycle can take longer than under normal conditions, but allow the pump start-up process to occur more quickly, thereby greatly reducing the total time required for pump start-up operations. Pump cooling and maintenance of the pump at the cooling temperature can be provided in such a way that the pump can be started up quickly (e.g., within 5 minutes, less than 5 minutes but more than 5 seconds, up to 2 minutes, up to 3 minutes, between 10 seconds and 2.5 minutes, between 5 seconds and 4 minutes, etc.). Embodiments may be provided such that the pump temperature can be maintained at the desired cooling temperature while minimizing hydrogen loss, which also avoids the need to immerse the pump in liquid hydrogen. The embodiments can also be configured to maintain the pump's cooling temperature while avoiding the need to vent the downstream piping before the pump is operated.

[0008] Examples can be provided to reduce hydrogen loss in cryogenic hydrogen pump (CHP) systems or other cryogenic fluid pump systems. For example, some examples can reduce hydrogen loss by reducing the exhaust volume required for pump cooling. Examples can also facilitate pump startup with a pressurized exhaust line, which reduces losses and startup time. Examples can also allow for faster startup times, enabling direct refueling of vehicles, which minimizes the need for gas storage or secondary pre-cooling systems for refueling stations. We believe that examples can additionally provide effective cooling by allowing gas to flow along an exhaust path inside the pump, which can allow for a significant reduction in hydrogen loss compared to pumps that are traditionally considered to offer rapid start-up operation by fully immersing them to maintain their temperature.

[0009] Some embodiments can support cooling operations by utilizing a leakage loop using a control valve that allows fluid to flow to the atmosphere. In a preferred embodiment, the control valve may be a pneumatic control valve that allows fluid to be discharged to an external environment, for example, at atmospheric pressure. The cooling period may be considerably long, depending on the pump temperature at the start of the cooling operation. In some cases where the pump is at ambient temperature, the cooling operation may take up to two hours. Once the pump is at its cooling temperature, it can be maintained at that temperature to facilitate rapid start-up (e.g., for 5 seconds to 5 minutes, less than 3 minutes, less than 2 minutes, for 5 seconds to 2.5 minutes, for 10 seconds to 3 minutes, etc.). In other cases, the pump can be cooled rapidly, requiring a shorter cooling period. The pump can then undergo a start-up operation after being cooled to its operating temperature within a short period (e.g., for 5 seconds to 5 minutes, less than 3 minutes, less than 2 minutes).

[0010] At least one temperature sensor can also be used to help monitor the pump temperature. In some embodiments, one or more temperature sensors may include a first temperature sensor, which may be positioned at or near the pump outlet to monitor the pump temperature. A second temperature sensor may also be provided to monitor the temperature elsewhere within the pump (e.g., a sensor near or at the pump feed inlet). The temperature sensors can help monitor the temperature of hydrogen or other cryogenic fluids used for cooling operations to help verify that the flow rate is cold enough to provide the desired cooling operation. Examples of temperature sensors TE may include thermocouples or other suitable types of temperature sensors.

[0011] Some embodiments may utilize a device configured to allow liquid hydrogen fuel and / or very cold gases (e.g., cryogenic hydrogen in a storage tank) to pass through the pump to the pump inlet when the pump is not operating. A venting circuit to the atmosphere or other venting assembly may be coupled to the pump and open when the pump is not operating, through which cooling fluid flows to cool the pump, thereby helping to drive the fluid to flow through the pump at a preselected rate, preferably a slow or low rate. Once it is determined that the pump is at or below a preselected operating temperature and there is a demand for fluid at the distributor, the pump can be started. In some embodiments, pump start-up can occur almost instantly (e.g., within minutes, in less than two minutes, in the range of 0.25 minutes to 2 minutes, or in the range of 1–30 seconds, etc.) without purging the downstream piping system or allowing product to flow through the pump to the atmosphere (although this function can still be provided by the venting circuit or other venting assembly for use when needed due to unexpected performance problems, component failures, etc.). In some embodiments, this significantly increased pump start-up time may occur due to a cooling process used to cool the pump to its operating temperature. In other embodiments, this significantly improved pump start-up time is provided by utilizing cryogenic flows of liquid and / or gas that can be output from a tank in fluid communication with the pump.

[0012] Other embodiments can be configured such that the pump cylinder is sized and configured to allow cold gases (e.g., cryogenic gases), liquid hydrogen, or other cold fluids (e.g., cryogenic fluids such as cryogenic oxygen, cryogenic helium, cryogenic nitrogen, or cryogenic hydrogen) to cool the pump through parallel paths within the pump cylinder. These parallel paths can be used independently, not at all, or in conjunction with a main flow path defined to allow cooling fluid to flow around the piston rings. For example, this additional path for cooling fluid can be used to compensate for variations in ring wear, or if the pump's idle piston position limits the flow rate through the pump.

[0013] An apparatus for hydrogen storage and distribution is provided. The apparatus may include a pump positioned to receive hydrogen from at least one storage tank. The pump may have a pump discharge outlet for a pump discharge conduit through which liquid flows out of the pump. The pump may also have a compression chamber and a movable piston movable within the compression chamber. The pump may also have piston rings positioned near the compression chamber and the movable piston. The piston rings and the compression chamber may be positioned and configured such that hydrogen gas can enter the compression chamber when the piston is stationary and can flow from the compression chamber through the piston rings to a cooling outlet configured to be in fluid communication with a cooling discharge conduit for discharging the hydrogen gas to the atmosphere.

[0014] The cooling discharge pipe can be separated from the pump discharge pipe, allowing compressed liquid to exit the pump via the pump discharge pipe. For example, fluid exiting the pump and passing through the pump discharge pipe will not pass through the cooling discharge pipe. Furthermore, fluid exiting the pump and passing through the cooling discharge pipe may not pass through the pump discharge pipe.

[0015] Embodiments of the apparatus for hydrogen storage and distribution may further include the storage tank and hydrogen feed piping assembly. The hydrogen feed piping assembly may include at least one of: (i) a liquid feed piping connected between the storage tank and the feed inlet of the pump to supply liquid hydrogen from the storage tank to the pump, and (ii) a hydrogen supply piping connected between the storage tank and the feed inlet of the pump to supply hydrogen from the storage tank to the pump. Embodiments of the apparatus may further include a cooling discharge piping. The cooling discharge piping may be connected to the pump, so that hydrogen passing through the cooling outlet can exit the pump and pass through the cooling discharge piping for discharge during cooling operation of the pump.

[0016] The cooling discharge conduit may have an adjustable valve that can be adjusted to an open position to discharge hydrogen during the pump's cooling operation when the pump is not in use. The adjustable valve may also be closed to prevent venting. When closed, the cooling discharge conduit may include a section to supply hydrogen passing through the conduit back to the storage tank, thus serving as a return flow for leaked vapors from the pump.

[0017] In some embodiments, the device may include one or more temperature sensors. For example, embodiments may include at least one of: (1) a first temperature sensor connected to the pump to measure the temperature of hydrogen fed from the tank to the pump; and (2) a second temperature sensor connected to the cooling discharge pipe to monitor the temperature of hydrogen output from the pump through the cooling discharge pipe. Embodiments may also include a controller communicatively connected to the first and / or second temperature sensors to determine the difference between the temperature of hydrogen fed from the tank to the pump and the temperature of hydrogen output from the pump and through the cooling discharge pipe. The controller may include hardware (e.g., a processor connected to a non-transitory computer-readable medium and at least one transceiver or interface for communicating with the temperature sensors). The controller may be configured to determine that the pump is at a temperature within a preselected operating temperature range and, in response to determining that the difference is within a preselected pump operating temperature threshold, determine that the pump can be activated to feed hydrogen to the dispenser.

[0018] The controller can be configured to regulate the valves of the hydrogen feed pipeline assembly and communicate with the pump drive motor to turn on the pump in response to determining that the pump is at a temperature within the preselected pump operating temperature threshold and that the difference is within the preselected pump operating threshold.

[0019] In some embodiments, the pump may include at least one internal cooling passage positioned to deliver a portion of the hydrogen to internal pump components after the hydrogen has passed through the piston, while moving along a cooling flow path toward the cooling flow outlet. For example, the cooling passage may be defined within the cylinder of the pump.

[0020] A method for performing pump cooling operation is also provided. Embodiments of the method allow for rapid pump start-up. Embodiments of the method may include opening a valve on a cooling discharge line connected to the pump in fluid communication with a storage tank, such that hydrogen from the storage tank can enter the pump's compression chamber when the pump is stopped. The method may further include allowing hydrogen to flow from the storage tank into the pump while the pump's piston is stationary, thereby causing hydrogen that entered the compression chamber while the piston is stationary to flow out of the compression chamber and through piston rings positioned near the compression chamber and the piston. The hydrogen can flow from the piston rings to the cooling discharge line for discharge.

[0021] Embodiments of the method may further include other steps. For example, the method may further include determining that the pump is cooled to a temperature within a pre-selected operating pump temperature range, and in response to determining that the pump is within the pre-selected operating pump temperature range and that there is a demand for liquid hydrogen at a distributor fluidly connected to the pump, closing a valve in the cooling discharge line to stop the discharge of hydrogen, and turning on the pump drive motor to start the pump for moving the piston of the pump within the compression chamber to feed liquid hydrogen from the storage tank to at least one distributor.

[0022] As another example, the embodiment may also include monitoring the temperature of hydrogen passing through a portion of the pump to measure the temperature of hydrogen fed from the storage tank to the pump, and monitoring the temperature of hydrogen exiting the pump to pass through the cooling discharge pipe. A first temperature sensor may be connected to the pump to measure the temperature of hydrogen passing through a portion of the pump, and a second temperature sensor may be connected to the cooling discharge pipe to measure the temperature of hydrogen exiting the pump to pass through the cooling discharge pipe.

[0023] Embodiments of the method may utilize a controller. The controller may include hardware, such as a processor connected to at least one transceiver or interface and a non-transitory computer-readable medium. The controller may be communicatively connected to the first temperature sensor and / or the second temperature sensor to determine whether the pump is at or below a pre-selected pump operating temperature threshold. In response to determining that the pump is at or below the pre-selected pump operating temperature threshold, the controller may send communications to close a valve in the cooling discharge line to stop the discharge of hydrogen.

[0024] In some embodiments, the method may further include determining the temperature difference between the temperature of hydrogen passing through the pump and the temperature of hydrogen exiting the pump and passing through the cooling discharge conduit. In response to determining that (i) the difference is within a pre-selected pump operating temperature threshold, (ii) the temperature of the hydrogen passing through the pump is within a pre-selected pump operating temperature range, and (iii) there is a demand for liquid hydrogen at a distributor fluidly connected to the pump, the valve of the cooling discharge conduit may be closed to stop the discharge of hydrogen, and the pump drive motor may be turned on to start the pump for moving the piston of the pump within the compression chamber to feed liquid hydrogen from the storage tank to the distributor.

[0025] In other embodiments, the method may include determining the temperature within the pump within a pre-selected operating temperature range of the pump via a temperature sensor connected to the pump, the temperature sensor being positioned such that a distal measuring point of the temperature sensor is located at a pre-selected detection location within the pump, the pre-selected detection location being adjacent to the bottom of the pump and / or a weir within the pump. In response to determining that the temperature within the pump is within the pre-selected operating temperature range and that there is a demand for liquid hydrogen at a distributor fluidly connected to the pump, a valve on the cooling discharge line is closed to stop the discharge of hydrogen, and a pump drive motor is activated to start the pump for moving the pump's piston within the compression chamber to feed liquid hydrogen from the storage tank to the distributor.

[0026] A pump for a cryogenic fluid storage and distribution device is also provided. Embodiments of the pump may include a piston connected to a movable piston rod for movement within a compression chamber and piston rings positioned near the compression chamber and the piston. The pump may also have a pump discharge outlet for a pump discharge conduit through which the cryogenic liquid flows out of the pump. The piston rings and the compression chamber may be configured such that cryogenic gas can enter the compression chamber when the piston is stationary, thereby allowing the cryogenic gas to flow through the compression chamber and through the piston rings toward a cooling outlet configured to be in fluid communication with a cooling discharge conduit for discharging the cryogenic gas.

[0027] Embodiments of the pump may include other components. For example, the pump may include the cooling discharge conduit, and the cooling outlet may be in fluid communication with the cooling discharge conduit. In some embodiments, the cooling outlet may be located on the non-compression side of the piston.

[0028] The cryogenic gas that can be used in the pump can be (i) hydrogen, nitrogen, oxygen, or helium. In an embodiment where the cryogenic gas is hydrogen, the liquid fed into the compression chamber of the pump can be cryogenic liquid hydrogen. In an embodiment where the cryogenic gas is nitrogen, the liquid can be cryogenic liquid nitrogen. In an embodiment where the cryogenic gas is oxygen, the liquid can be cryogenic liquid oxygen. In an embodiment where the cryogenic gas is helium, the liquid can be cryogenic liquid helium.

[0029] The liquid that can flow out of the pump via the pump's discharge outlet can be liquid that is pushed out of the pump by a piston movement that occurs in the compression chamber when the pump is operated to drive the liquid out of the pump. The liquid discharged from the pump via the pump's discharge outlet can also be referred to as compressed liquid.

[0030] In some cases, the cryogenic gas can be, or can be, cryogenic oxygen, cryogenic nitrogen, cryogenic helium, or cryogenic hydrogen, or can be vapor formed from cryogenic liquid entering the pump when the pump is stopped. For example, the cryogenic hydrogen can be formed from cryogenic liquid hydrogen fed into the pump, which evaporates into hydrogen gas when the liquid hydrogen cools the pump. The cryogenic nitrogen can be nitrogen gas formed from liquid cryogenic nitrogen fed into the pump, which evaporates into nitrogen gas when the liquid nitrogen cools the pump. The cryogenic oxygen can be oxygen gas formed from cryogenic liquid oxygen fed into the pump, which evaporates into oxygen gas when the liquid oxygen cools the pump. Cryogenic helium, as helium, can be formed from cryogenic liquid helium fed into the pump, which evaporates into helium gas when the liquid helium cools the pump.

[0031] Further details, objectives, and advantages of our devices for hydrogen storage and distribution, devices for cooling pumps (which can be positioned and configured to facilitate hydrogen fuel distribution and / or storage), pump cooling devices for cryogenic operation of said pumps, and methods for manufacturing and using these devices will become apparent from the following description of some exemplary embodiments thereof. Attached Figure Description

[0032] Exemplary embodiments of devices for hydrogen storage and distribution, devices for cooling pumps (which may be positioned and configured to facilitate hydrogen fuel distribution and / or storage), pump cooling devices for cryogenic operation of said pumps, and methods for manufacturing and using these devices are shown in the accompanying drawings. It should be understood that the same reference numerals used in the drawings may identify the same parts.

[0033] Figure 1 This is a schematic block diagram of a first exemplary embodiment of a hydrogen fuel distribution and storage device.

[0034] Figure 2 This is a schematic diagram of a first exemplary embodiment of a device for cooling pump 5, which can be utilized in a first exemplary embodiment of a hydrogen fuel distribution and storage facility. The controller CTRL can have exemplary communication connections with various components (e.g., pump 5, temperature sensor TE, control valve 4acv, etc.). Figure 2 The middle part is indicated by a dashed line, with an arrow at the end of the dashed line.

[0035] Figure 3 yes Figure 2 The diagram shows a partial interior view of a first exemplary embodiment of the device for cooling a pump, wherein the pump 5 of the device is configured as a horizontal pump.

[0036] Figure 4 yes Figure 2 The diagram shows a partial interior view of a first exemplary embodiment of the device for cooling a pump, wherein the pump 5 of the device is configured as a vertical pump. Figure 4 The vertical axis 5 is shown to help illustrate the vertical direction of pump 5. Detailed Implementation

[0037] refer to Figures 1 to 4 The hydrogen fuel distribution and storage facility may include a storage tank 3 configured to store liquid hydrogen therein at a pre-selected pressure. The hydrogen stored in the storage tank may be fed via one or more trailers, which may have already transported the liquid hydrogen to a facility for storage in tanks, pipelines, or an on-site hydrogen generation system 2 (shown in dashed lines).

[0038] The hydrogen generation system 2 may include, for example, an ammonia cracker system having at least one ammonia (NH3) cracker system for cracking ammonia to form hydrogen, or a methane reformer system having at least one methane reformer for reforming methane to form hydrogen (H2). The hydrogen generation system 2 may be configured to separate the generated hydrogen from other gases (e.g., nitrogen, carbon dioxide, etc.) using a purification system or a gas separation system. Such a purification system may include, for example, a pressure swing adsorption (PSA) system and / or a temperature swing adsorption (TSA) system. Alternatively, other types of purification systems may also be used. In some embodiments, the hydrogen output from the hydrogen generation system 2 may be purified such that the hydrogen output from the hydrogen generation system is at least 99.5 mol% or at least 99.7 mol% hydrogen (e.g., in the range of 99.7 mol% to 99.999 mol%). The hydrogen output from or received from the hydrogen generation system 2 may be liquefied for storage in a storage tank 3, or liquefied for transport to be delivered and stored in a storage tank 3 at a fuel refueling station site.

[0039] Storage tank 3 may include one or more containers in which liquid hydrogen is stored at a pre-selected storage temperature and a pre-selected storage pressure. The stored hydrogen may be liquid hydrogen stored at cryogenic temperatures. For example, the temperature at which the liquid hydrogen is stored may be in the temperature range of -255°C to -241°C, below -255°C, below -240°C to -255°C, in the range of -253°C and -241°C, or in another suitable temperature range that allows the hydrogen to remain in liquid form while being within the pre-selected storage pressure range. The pressure of the stored liquid hydrogen can be greater than 9 to 12.07 atm, greater than 1 atm to less than 12 atm, or greater than 9 atm and less than 12 atm, between 9.0 atm and 11.6 atm, or in another suitable pressure range selected to keep the liquid hydrogen in liquid form while keeping it within a pre-selected storage temperature range (e.g., 0.2 MPa to 1.1 MPa, above 0.2 MPa, 0.5 MPa to 1.2 MPa, above 10 psig and below 135 psig, etc.).

[0040] When liquid hydrogen 3L is stored in tank 3, hydrogen gas 3G may form in the tank. This hydrogen gas 3G can be discharged from tank 3 to provide cooling for pump 5 via a cooling process as discussed below. Hydrogen gas 3G can be used alone and / or in conjunction with the supply of liquid hydrogen 3L to provide cooling operation and / or rapid start-up operation. In other cases, liquid hydrogen 3L can be used for cooling operation and / or rapid start-up operation without the use of hydrogen gas 3G.

[0041] In embodiments where an on-site hydrogen generation system 2 is present, storage tank 3 can store hydrogen output from hydrogen generation system 2 to hold the hydrogen therein until a demand for hydrogen from at least one distributor 9 at the fuel station necessitates the release of the stored hydrogen from storage tank 3 to be fed to one or more distributors 9 via at least one pump 5 and a flow control manifold (FCM) 7. The hydrogen output from the hydrogen generation system can be liquefied to be stored as liquid hydrogen in storage tank 3. In other embodiments, storage tank 3 can be configured to store hydrogen at a pre-selected storage temperature and a pre-selected storage pressure to hold the liquid hydrogen therein until a demand for hydrogen from at least one distributor 9 at the fuel station necessitates the release of the stored hydrogen from storage tank 3 to be fed to one or more distributors 9 via at least one pump 5 and a flow control manifold (FCM) 7.

[0042] In some embodiments, the hydrogen stored in at least one storage tank 3 may be at least 99.97 mol%. In some embodiments, the stored hydrogen may also include an impurity concentration of up to 300 ppm (e.g., ranging from 0 ppm to 300 ppm). Impurities up to 300 ppm (e.g., impurities with a cumulative total range from 0 ppm to 300 ppm) may include water present in the range of 0 ppm to 5 ppm, total hydrocarbons in the range of 0 ppm to 2 ppm excluding methane or other single carbon equivalent hydrocarbons, oxygen in the range of 0 ppm to 5 ppm, methane in the range of 0 ppm and 100 ppm, helium in the range of 0 ppm to 300 ppm, nitrogen in the range of 0 ppm to 300 ppm, argon in the range of 0 ppm to 300 ppm, carbon dioxide in the range of 0 ppm to 2 ppm, carbon monoxide in the range of 0 ppm to 0.2 ppm, total sulfur compounds in the range of 0 ppm to 0.004 ppm, formaldehyde in the range of 0 ppm to 0.2 ppm, formic acid in the range of 0 ppm to 0.2 ppm, ammonia in the range of 0 ppm to 0.1 ppm, and halogenated compounds in the range of 0 ppm to 0.05 ppm.

[0043] Hydrogen stored in tank 3 can be fed to FCM 7 for delivery to at least one distributor 9 for distribution to fuel tanks of vehicles (e.g., cars, trucks, boats, etc.). Hydrogen feed line 4 can be positioned to feed hydrogen from tank 3 to pump 5, such that pump 5 can increase the pressure of hydrogen to a pre-selected hydrogen feed pressure and facilitate the flow of hydrogen from tank 3 to FCM 7.

[0044] Liquid hydrogen output from pump 5 can be fed to heat exchanger 6 (e.g., evaporator, other type of heat exchanger, etc.) to heat the hydrogen output from pump 5 to a pre-selected temperature within a pre-selected temperature range. A portion of the hydrogen output from the pump can bypass heat exchanger 6 via bypass pipe 6a. Bypass pipe 6a may include bypass pipe assembly 6bp, which includes one or more control valves 6acv to control the portion of hydrogen output from pump 5 bypassing heat exchanger 6 via bypass pipe 6a. The bypass portion can be fed to mix with the portion of hydrogen output from heat exchanger 6, such that the hydrogen fed to FCM7 is at a pre-selected temperature or within a pre-selected temperature range. The bypass portion can allow heat exchanger 6 to operate more efficiently, thereby reducing the capacity required for heat exchanger 6 to heat hydrogen via the bypass portion. This can reduce operating costs and provide more efficient operation of heat exchanger 6.

[0045] In some embodiments, the bypass pipe assembly 6bp for bypass pipe 6a may include a separate refrigeration or cooling system to help provide temperature control for the hydrogen flow fed to the FCM and / or distributor. While this can be utilized, it is also contemplated that embodiments may be configured such that the utilization of the cooling process discussed herein can reduce the need for a refrigeration system (e.g., allow its avoidance or allow the use of a smaller system), due to the rapid start-up of pump 5 and the relatively instantaneous refueling of the vehicle fuel tank provided by embodiments of pump 5 utilizing our cooling process.

[0046] In other embodiments, the first bypass conduit 6a can be used to bypass the heat exchanger so as to subsequently mix with the hot hydrogen output from the heat exchanger 6. A separate second conduit assembly may be present to provide additional venting options as a backup or supplement to the venting that can be provided by the cooling exhaust conduit 4b.

[0047] FCM7 may be fluidly connected between pump 5 and at least one distributor 9 to receive hydrogen from the bypass assembly 6bp of heat exchanger 6 and / or bypass line 6a for feeding hydrogen to at least one distributor 9 for distribution into the vehicle's fuel tank. Other units may be located between pump 5 and FCM7. For example, at least one heat exchanger 6 may be present downstream of pump 5 and upstream of FCM7 for heating the hydrogen after its pressure is increased via pump 5, to heat the hydrogen to a pre-selected FCM feed temperature before it is received at the FCM.

[0048] In some embodiments, a second pump (not shown) may be present, positioned to operate in parallel with and / or as a backup pump for the first pump 5. In such embodiments where the second pump is arranged to operate in parallel with the first pump 5, the second pump may utilize similar flow paths and piping assemblies. For example, a second heat exchanger (not shown) positioned between the second pump (not shown) and FCM7 may also be present to regulate the temperature of the hydrogen output from the second pump before receiving hydrogen at FCM7. When the second pump is used as a backup pump, it may be connected to the same piping as the first pump and brought online in place of the first pump due to maintenance or repair issues or other problems that may affect the operation of the first pump.

[0049] A high-pressure storage tank 8, fluidly connected to the FCM 7, may also be present to receive hydrogen from the FCM for storing hydrogen at a higher pressure after the hydrogen pressure has been increased via the pump 5 and bypassed through the heat exchanger 6 and / or for cooling the output of the heat exchanger 6. The high-pressure storage tank 8 can maintain the hydrogen therein at a second pressure higher than the first pressure of the storage tank 3. The pressure used for this higher-pressure storage can be set higher than the pressure to be maintained in the vehicle tank to facilitate the distribution of hydrogen into the tank via the FCM 7 and / or the distributor 9.

[0050] The FCM7 can be fluidly connected to one or more distributors 9 of a fuel distribution system to supply hydrogen to the distributors for distribution to at least one fuel tank in one or more vehicles or other equipment. The FCM7 can be configured to simultaneously distribute hydrogen to one or more distributors at a fuel station to supply hydrogen to the distributors for fuel tanks in different vehicles or other equipment located near the hydrogen-receiving distributor. Hydrogen feeding at the distributor can occur after or before hydrogen payment has already been made at the fuel station or at the fuel station distributor automated service terminal (kiosk).

[0051] Even if not for most of the day, hydrogen refueling stations may typically operate for many hours with little or no use. However, when in use, the demand for hydrogen at a refueling station can be significant. Generally, sufficient storage space is provided for hydrogen fuel so that the station can meet high demand when needed. When high-demand conditions occur (e.g., when vehicles need to be refueled at the station, when multiple vehicle refueling tanks are being refueled at the station, etc.), it may be necessary to quickly start pump 5 to help drive the hydrogen from storage tank 3 and to FCM 7 for distribution via one or more dispensers. We determined that allowing for faster pump start-up would be beneficial, allowing the refueling station to adjust from no-demand to high-demand conditions more quickly, thus avoiding excessive delays in refueling vehicle refueling tanks at refueling dispenser 9. In some embodiments, this faster start-up can be provided by using a cooling operation as part of a rapid start-up process, which allows the pump to cool to the desired operating temperature within a relatively short period of time (e.g., less than 10 minutes, less than 5 minutes, less than 2.5 minutes, but also longer than 5 seconds). In other embodiments, this faster start-up time can be provided by a cooling operation that may take a considerable amount of time (e.g., up to 2 hours, more than 30 minutes, but less than 3 hours, etc.), the function of which is to bring the pump 5 to the desired operating temperature so that the pump can be used for rapid start-up based on the demand present at the dispenser, while also avoiding the significant hydrogen loss that may occur with conventional pump immersion methods. The embodiments can address high-demand situations to provide faster start-up, while also addressing other situations where demand exists at the dispenser of a refueling station that is not necessarily considered a high-demand event.

[0052] We also determined that providing rapid start-up of pump 5 can help minimize or eliminate the need for higher pressure storage. Providing higher pressure storage can be relatively expensive and may consume significant space at a refueling station. By using pump 5, which can be started within a relatively short period of time (e.g., within 0.5–5 minutes when the dispenser is actuated to supply fuel to the vehicle), higher pressure storage can be minimized, even if not eliminated. This advantageous feature can be particularly useful in embodiments where pump 5 can remain operational very quickly without additional heat load on the cryogenic tank (e.g., low-pressure tank 3) or with significant additional heat load on the tank. For example, maintaining the pump at a pre-selected cooling temperature to avoid significant hydrogen loss from hydrogen stored in low-pressure tank 3 can help improve the efficiency provided by the rapid start-up feature of pump 5.

[0053] For example, some embodiments of the cooling process can minimize wasted hydrogen product by first cooling the pump with cold hydrogen from tank 3 (reducing heat load by removing hotter vapor from tank 3). This type of cooling can also help prevent the liquid hydrogen fed to pump 5 from evaporating due to the temperature of the pipe leading to pump 5, causing the formed vapor to prevent liquid from reaching pump 5, as vapor formed by boiling liquid cannot return to the tank via the pipe through which it is fed. Such vapor may need to be vented (and subsequently lost) to allow liquid to pass through pump 5, which can reduce the heat load on tank 3 and can provide further pump cooling. Embodiments of the cooling process that prevent liquid from entering pump 5 during cooling operations can reduce the generation of gases and the need to vent gases formed as the liquid flows from tank 3 to pump 5 due to boiling into vapor. Such cooling operations can help facilitate rapid, efficient pump start-up in response to demand at distributor 9.

[0054] like Figures 2 to 4 As shown, pump 5 can be arranged and configured to facilitate improved cooling operation, allowing pump 5 to be started within a relatively short time period (e.g., less than five minutes, less than or equal to two minutes, less than or equal to 30 seconds, in the range of 15 seconds to 3 minutes, or 5 seconds to 2.5 minutes, etc.). Cooling operation can be performed so that pump 5 can be started without discharging downstream piping systems or allowing product to flow through pump 5 into the atmosphere (although this function can still be provided via the pump discharge piping assembly for use when needed due to unexpected performance issues, component failures, etc.). This improved cooling operation can allow refueling stations to adapt to demand more quickly and allows for improved operation of refueling stations for faster filling of vehicle tanks or otherwise allows dispensers to be operated for filling fuel tanks. We believe that, compared to the pump immersion method, the embodiments can also provide substantial improvements in avoiding hydrogen loss by significantly reducing the amount of stored hydrogen lost. Furthermore, the embodiments can allow for the need for less high-pressure storage capacity, or can allow for the elimination of high-pressure storage.

[0055] The hydrogen feed line assembly 4 may include a conduit that fluidly connects the storage tank 3 to the pump 5 and fluidly connects the pump 5 to the FCM 7 and the distributor 9. For example, the hydrogen feed line assembly 4 may include a liquid feed line 4a connecting the storage tank 3 and the feed inlet 5a of the pump 5 to feed liquid hydrogen 3L to the pump 5. The hydrogen feed line assembly 4 may also include a hydrogen supply line 4g, which may be configured to receive hydrogen 3G from the storage tank 3 and output hydrogen 3G to feed the hydrogen to the pump 5 to perform pump cooling operations.

[0056] In some embodiments, the pump 5 may have a feed inlet 5a, which includes a plurality of supply inlets, including a gas supply inlet 4go in fluid communication with a gas supply conduit 4g and a liquid supply inlet 4ao in fluid communication with a liquid feed conduit 4a. In other embodiments (such as...) Figure 2 (As shown by the dashed line), pump 5 may include a feed inlet 5a having a single supply inlet in fluid communication with both gas supply conduit 4g and liquid supply conduit 4a. In embodiments with a single supply inlet, gas supply conduit 4g may include a segment 9g (shown by the dashed line) connected to liquid supply conduit 4a, such that a mixture of liquid and gas, or gas only, can be delivered to pump 5 via the single pump feed inlet 5a. It should be understood that this segment 9g of gas supply conduit 4g may also exist in embodiments where multiple supply inlets of pump 5 can be used to provide additional flow path options for cooling operations or other operations.

[0057] Cooling vent pipe 4b can be connected to pump 5 to facilitate the venting of hydrogen to the atmosphere, allowing hydrogen passing through the pump to perform cooling operations to be vented. This ensures that the cooled hydrogen output from pump 5 during cooling operations is not transferred downstream of pump 5 (e.g., not downstream to heat exchanger 6 or FCM7). The hydrogen venting also provides a pressure differential to help drive hydrogen flow from storage tank 3 to pump 5, and subsequently out of the pump for venting, allowing the pump to be cooled to a pre-selected operating temperature or maintained at such temperature without the need for additional equipment to assist in driving the hydrogen flow for cooling operations.

[0058] The pump discharge pipe 4d of the hydrogen feed piping assembly 4 connects the pump 5 to the heat exchanger 6 and the FCM 7, such that liquid hydrogen output from the pump 5 via the pump discharge outlet 4d can be heated by the heat exchanger 6 to a desired pre-selected FCM feed temperature within a pre-selected temperature range, and then delivered to the FCM 7 via the FCM feed pipe 4e of the hydrogen feed piping assembly 4, which can connect the heat exchanger 6 and the FCM 7. The pump discharge pipe 4d can be separated from the cooling discharge pipe 4b. Hydrogen discharged from the pump via the cooling discharge pipe 4b can bypass a portion of the pump discharge pipe 4d. Furthermore, hydrogen output from the pump 5 via the pump discharge pipe 4d does not pass through the cooling discharge pipe 4b, because the hydrogen delivered to the pump discharge pipe 4d is directed toward the FCM 7 and at least one distributor 9.

[0059] The preselected temperature range can be a temperature close to the temperature at which fuel is dispensed into the fuel tank to help minimize the heat of compression within the vehicle's fuel tank. In some embodiments, the preselected temperature range can be no lower than -40°C and no higher than 50°C, between -20°F and -40°F, or between -25°C and -40°C.

[0060] The hydrogen feed line assembly 4 may also include a hydrogen bypass line assembly 6bp connected to the pump discharge line 4d, allowing hydrogen to be discharged into the atmosphere via the exhaust line 4f as an auxiliary or backup means of pump cooling, and / or a portion of the hydrogen can bypass the heat exchanger 6 via the heat exchanger bypass line assembly 6bp to be used for mixing with the hydrogen fed to the FCM 7 to maintain the hydrogen within a desired temperature range before it is delivered to the FCM 7. Using a bypass line assembly to allow a portion of the hydrogen to bypass the heat exchanger 6 can help reduce the load on the heat exchanger 6, saving on operating costs for maintaining the hydrogen within the desired pre-selected FCM feed temperature range. For example, to provide such a bypass flow to bypass the heat exchanger 6, the control valve 4acv for the downstream exhaust of the pump 5 and the line can be closed, while other valves within the bypass line assembly 6bp are opened to allow a portion of the hydrogen flow through the bypass line assembly to bypass the heat exchanger 6, so as to subsequently mix with the heated portion of the hydrogen passing through and exiting the heat exchanger 6.

[0061] Check valves 4cv can be located in piping assembly 4. Each check valve 4cv can be configured to prevent hydrogen from flowing backward in the hydrogen feed piping assembly, thereby preventing hydrogen from flowing backward from the check valve 4cv after it has passed through it (e.g., back upstream to tank 3 or pump 5). For example, at least one check valve 4cv can be located between heat exchanger 6 and pump 5 such that hydrogen cannot flow back towards pump 5 after it has passed through the check valve. As another example, at least one check valve 4cv can be connected to cooling discharge line 4b such that hydrogen discharged from pump 5 during cooling operation cannot flow back to the pump after it has passed through the check valve 4cv.

[0062] The hydrogen feed line assembly 4 may also include an adjustable control valve 4acv. The adjustable control valve 4acv can be adjusted between a fully closed and a fully open position to guide fluid through the hydrogen feed line assembly 4 along a desired flow path.

[0063] For example, a first adjustable control valve 4acv1 can be connected to and open the cooling discharge pipe 4b to allow hydrogen to be released into the atmosphere and to provide a pressure differential, thereby enabling the hydrogen and / or liquid flowing from the tank to be fed to pump 5 for cooling operations before the pump begins operation to drive liquid flow toward FCM7 and / or distributor 9. A second adjustable control valve 4acv2 can be located between the storage tank and the cooling discharge pipe 4b, and remains closed when the first adjustable control valve 4acv is open, and opens when the first adjustable control valve 4acv is closed, to allow hydrogen to return toward tank 3 when the pump is operated to drive liquid hydrogen toward distributor 9 and / or FCM7.

[0064] The bypass piping assembly 6bp may include a third adjustable control valve 4acv3, a fourth adjustable control valve 4acv4, and a fifth adjustable control valve 4acv5. The third adjustable control valve 4acv3 may be an unloading valve, which can open to allow venting of the piping between pump 5 and heat exchanger 6. For this venting, the fourth adjustable control valve 4acv4 may be in the closed position, while the fifth adjustable control valve 4acv5 may be in the open position. The fifth adjustable control valve 4acv5 may be closed, and the third and fourth adjustable control valves 4acv3 and 4acv4 may be open to facilitate the flow of hydrogen, which can bypass heat exchanger 6 and be mixed back into the liquid output from heat exchanger 6.

[0065] The temperature sensor TE can also be connected to different units of the hydrogen feed piping assembly 4 and / or equipment (e.g., pump 5, etc.). The temperature sensor TE can measure the temperature of the hydrogen within the piping and / or pump 5 to monitor pump operation, cooling operation status, or other conditions, wherein the measured temperature can be correlated with equipment operation. In some embodiments, the temperature sensor can be a thermocouple or other type of temperature sensor. Embodiments can also utilize flow sensors, pressure sensors, or other types of sensors to monitor operations for automated control of the operation of pump 5, piping assembly 4, valves, and other units. Such sensors can be communicatively connected to the controller CTRL or other units of the automated process control system, so that measurement data obtained from the sensors can be fed to the control system for monitoring equipment operation and automating equipment operation.

[0066] As from Figure 3 and Figure 4 As best understood, pump 5 may include cylinder 5C and movable piston 5p. Movable piston rod 5r extends through cylinder to piston 5p to move piston 5p, such that piston 5p is adjustably positioned within compression chamber 5cav via retraction or extension of piston rod 5r to which piston 5p is attached, for increasing the pressure of hydrogen for feeding hydrogen from storage tank 5 to one or more distributors 9. Pump drive motor or other piston rod movement mechanism may be coupled to piston rod 5r to drive movement of piston 5p within compression chamber 5cav. Hydrogen may be received at pump inlet 5a and fed into compression chamber 5cav via main feed inlet 5fi. Compressed hydrogen fluid may be discharged from this chamber via pump discharge outlet 4do, which is connected to pump discharge conduit 4d due to the movement of piston 5p when pump drive motor is started and running to move piston 5p. Liquid hydrogen can then be received from the storage tank, fed into the compression chamber 5cav for compression therein, and flowed from the compression chamber 5cav to the pump discharge outlet 4do via the pump discharge valve 5dv.

[0067] Pump 5 can also be configured to allow a hydrogen gas flow through it during cooling operations. For example, hydrogen from tank 3 can enter compression chamber 5cav to cool the pump, such that when the pump is off or deactivated, hydrogen can enter compression chamber 5cav (e.g., piston 5p does not move via the movement of piston rod 5r driven by the pump drive motor to increase the hydrogen pressure for output via pump discharge outlet 4do). Hydrogen can be discharged from the tank via opening a valve connected to cooling discharge pipe 4b to release hydrogen into the atmosphere. Hydrogen from tank 3 can be output as hydrogen gas 3G via hydrogen supply pipe 4g and / or as liquid hydrogen via liquid feed pipe 4a. A hydrogen gas flow can be induced by opening a valve in cooling discharge pipe 4b to discharge hydrogen.

[0068] When the pump is shut off, hydrogen entering pump 5 can enter compression chamber 5cav via the main feed inlet 5fi as a cooling inlet cooling flow 5cfi, allowing the hydrogen to flow along a cooling path to cool the pump to a desired operating temperature within a pre-selected operating temperature range. The hydrogen flowing along this path can be used as hydrogen 3G or as a gas generated from liquid hydrogen 3L fed to the pump, which is heated within the pump and / or feed line, causing at least some of the liquid to transform into a gaseous state during cooling. This formed gas can flow along a cooling path that includes the inlet cooling flow 5cfi entering compression chamber 5cav, which then passes through other internal pump components before exiting the pump via cooling discharge line 4b for discharge to the atmosphere via exhaust.

[0069] The cooling path for cooling the pump to a desired operating temperature within a pre-selected operating temperature range can be defined such that a cooling flow of hydrogen passes from the compression chamber 5cav through piston ring 5pr, which is positioned near the compression chamber 5cav to aid in sealing the chamber. While piston ring 5pr is positioned to provide a seal between the movable piston 5p and the compression chamber 5cav during pump operation via the movement of piston 5p within the compression chamber 5cav, this seal is not a complete seal for hydrogen, and a hydrogen flow can pass through ring 5pr. This hydrogen flow during cooling operation... Figure 3 and Figure 4The image shows the initial hydrogen cooling flow 5cfr, a hydrogen cooling flow that flows from the compression chamber 5cav to the piston ring 5pr to provide a hydrogen cooling flow 5cf that moves along and passes through the piston ring during cooling operation. Hydrogen passes through the piston ring 5pr more easily when the rings are worn than when the piston rings are newer and unworn. When the piston 5p is not moving during cooling operation, hydrogen can flow out of the compression chamber 5cav and through the piston ring. The hydrogen cooling operation cooling flow path can pass through the piston ring and piston 5p along the segment 5cfp of the hydrogen cooling operation cooling flow, so as to be discharged along the piston rod 5r from the cooling flow outlet 4bo of the cooling discharge pipe 4b, which serves as the outlet segment 5cfo of the hydrogen cooling operation cooling flow. The outlet flow of the hydrogen cooling flow for cooling operation can pass through the cooling flow outlet 4bo to be discharged into the atmosphere via the cooling discharge pipe 4b.

[0070] The cooled hydrogen flow can flow along piston 5p and toward the cooling outlet 4bo of cooling discharge pipe 4b. Before passing through cooling outlet 4bo, the cooled hydrogen flow can pass through the uncompressible side of piston 5p, such as... Figure 3 and Figure 4 The hydrogen cooling flow path is shown in segment 5cfp. The cooling flow outlet 4bo can be a cooling flow discharge outlet, which is positioned such that the cooling flow of hydrogen flows from the uncompressible side of the piston (e.g., beyond the piston 5p and close to a portion of the piston rod 5r) before exiting from the cooling flow outlet 4bo. It can be connected to the cooling discharge pipe 4b for discharging the hydrogen cooling flow of the cooling operation to the outside atmosphere via the cooling discharge pipe 4b.

[0071] In some embodiments, at least one cooling passage 5ci may be defined in the pump 5, such that a portion of hydrogen gas can flow from the feed inlet 5a of the pump 5 to other internal parts of the pump 5 via at least one coolant passage 5ci in fluid communication with the feed inlet 5a of the pump 5. The cooling passage 5ci may be in fluid communication with the inside of the cylinder 5C or other pump parts for cooling other parts of the pump via hydrogen gas. In some embodiments, the cooling passage 5ci may be at least one drilled passage or other defined passage, such that… Figure 3 and Figure 4 The hydrogen cooling flow shown in section 5cfp, which flows toward the uncompressible side of piston 5p, can be used to cool other internal components of pump 5 via cooling channel 5ci.

[0072] In some embodiments, at least one cooling channel 5ci may be used to supplement the cooling hydrogen flow through the pump via the compression chamber 5cav during cooling operations, to help cool other internal components of the pump more effectively and quickly. In other embodiments, the internal cooling channel 5ci may be absent or not utilized.

[0073] Hydrogen for cooling via cooling passage 5ci can be discharged from the pump via cooling discharge pipe 4b and / or via vapor return from pump 5. For example, the hydrogen gas stream can pass through at least one cooling passage 5ci, which extends from a location adjacent to the piston rod 5r to a location adjacent to the pump's discharge valve 5dv and / or to an internal discharge path for discharging hydrogen via a discharge outlet 4do fluidly connected to the pump discharge pipe 4d and a discharge valve 5dv fluidly connected to the discharge outlet 4do. The hydrogen can then be returned to the compression chamber 5cav for discharge into the atmosphere via cooling discharge pipe 4b.

[0074] After the pump is started and pump operation begins via the movement of piston rod 5r, during the operation of pump 5, hydrogen can be allowed to leak back into tank 3 by adjusting control valve 4acv to the open position after closing valve 4acv, which allows discharge from cooling discharge line 4b. This allows hydrogen to flow out of pump 5 upon pump start-up and return to tank 3 via cooling discharge line 4b. For example, in some embodiments, control valve 4acv of cooling discharge line 4b can be adjusted to close the valve for venting and open the valve to allow hydrogen output via cooling discharge line 4b to be returned to tank 3 when the pump is started to compress liquid hydrogen to provide a hydrogen leakage path.

[0075] In an alternative configuration, pump 5 can be configured such that when the pump is activated to compress the fluid within compression chamber 5cav, hydrogen supply line 4g can provide hydrogen leakage. In this configuration, the valve on cooling exhaust line 4b for venting can be closed, allowing hydrogen leakage internally via the pump to hydrogen supply line 4g, making this line serve as a vapor return to storage tank 3, while pump 5 is activated to compress liquid hydrogen and feed it to FCM 7.

[0076] As described above, to facilitate the flow of hydrogen from tank 3 to pump 5 for cooling operations, the pump can be kept off (e.g., the pump drive motor can be kept off or not running). An adjustable control valve on the cooling discharge pipe 4b, which is in fluid communication with pump 5 and tank 3 via hydrogen feed pipe assembly 4, can be opened to discharge tank 3 to the outside atmosphere. Opening the cooling discharge pipe 4b (e.g., Figure 2The venting valve (shown in the Chinese text "Vent") regulates the pressure in the hydrogen feed line assembly 4, causing hydrogen to flow slowly from the storage tank 3 to the pump feed inlet 5a for the cooling operation discussed above along the hydrogen cooling flow path through the pump chamber 5cav before being discharged via the cooling discharge line 4b. Examples of such slow speeds may include rates of 0.53 kg / h + / - 30%, 0.1 kg / h to 0.8 kg / h, or 0.4 kg / h to 0.6 kg / h. As another example of slow speeds, some embodiments may utilize flow rates in the range of 0.1 kg / h to 0.6 kg / h.

[0077] The hydrogen flow may include hydrogen gas 3G via hydrogen supply line 4g and / or liquid hydrogen flow 3L via liquid feed line 4a. When the exhaust control valve is open, the control valves 4acv of these lines can be opened to facilitate hydrogen flow to pump 5 when the pump is shut down for cooling operations.

[0078] As a result of the cooling operation, a relatively small amount of hydrogen is lost due to hydrogen emissions into the atmosphere. However, this hydrogen loss is acceptable considering the significantly reduced time required for rapid start-up of pump 5 that can be provided by utilizing the cooling process.

[0079] Furthermore, the hydrogen used for cooling operations can be hydrogen gas 3G, or it can include hydrogen gas 3G that might otherwise need to be discharged from storage tank 3. Using hydrogen gas 3G for cooling operations prior to the discharge of gas 3G allows for more efficient utilization of this hydrogen gas 3G formed due to the storage of liquid hydrogen in the low-pressure storage tank 3. This can further improve operational efficiency by using the hydrogen gas for useful operational purposes before discharging it into the atmosphere.

[0080] In some cases where pump 5 is expected to be out of service for a relatively long period, cooling operations can be performed solely using hydrogen 3G. In some embodiments, this operation may result in cooling operations taking 1–3 hours. Once the pump is at the desired temperature, cooling operations can be maintained continuously or periodically using a cooling flow of hydrogen 3G. This helps to keep the pump at the desired temperature near anticipated times of high demand at refueling stations, while minimizing hydrogen loss by using gas in tank 3 that would otherwise need to be vented. This quick-start feature can also be used in other non-high-demand situations. For example, the quick-start feature is advantageous for feeding fuel to the vehicle's fuel tank during low-demand situations, as such a feature helps to minimize (if not eliminate) the need for high-pressure storage or other ground-based storage of hydrogen downstream of the pump.

[0081] In other cases, liquid hydrogen 3L can also be used for cooling operations. When the pump is stopped, the liquid hydrogen fed to pump 5 for cooling operations can cool the pump to the desired operating temperature more quickly, thus enabling the cooling operation to be performed more quickly (e.g., within 1-3 minutes, within 5 minutes, between 30 seconds and 3 minutes, between 30 seconds and 2 minutes, etc.). This use of liquid hydrogen can be used for cooling operations when demand at the distributor is unexpectedly high after the pump has been stopped for a sufficient period of time and has been heated to an excessively high temperature (e.g., above the temperature that might fall within the pre-selected operating temperature range). Liquid hydrogen 3L can be used alone or in combination with the use of hydrogen 3G in cooling operations. As mentioned above, when using liquid hydrogen, most of the liquid hydrogen may evaporate during the cooling process because it is heated by absorbing heat from the pump components and liquid feed lines during the cooling operation. The resulting hydrogen gas (which is formed by the heating of the liquid hydrogen caused by the use of liquid hydrogen as a cooling medium) can flow along the cooling path as described above.

[0082] Temperature sensors and other control elements communicatively connected to the controller CTRL can be used to monitor and control cooling operations. For example, a first temperature sensor TE can monitor the temperature of hydrogen entering the pump feed inlet 5a, and a second temperature sensor TE can be positioned to monitor the temperature of hydrogen being discharged to the atmosphere (e.g., exhaust gas) (e.g., the second temperature sensor TE is connected to the cooling exhaust pipe 4b). Temperature measurement data from the first and second temperature sensors TE can be sent to the controller CTRL for evaluation to monitor cooling operations, for subsequent control of other valves, and for initiating pump operation by starting the pump drive motor after the pump is operating at a sufficiently cold operating temperature within a pre-selected operating temperature range and after a demand for hydrogen as fuel is present at one or more distributors 9.

[0083] The controller CTRL may be a computer device having a processor connected to a non-transitory memory and at least one transceiver for communicating with sensors and other components of the plant and / or equipment. The controller may be configured to evaluate temperature data received from the temperature sensor TE to determine the difference between the inlet temperature of hydrogen fed to pump 5 for cooling operations (e.g., the temperature determined by data from a first temperature sensor TE that may be located in pump 5 or pump inlet 5a) and the outlet temperature of hydrogen discharged during cooling operations (e.g., the temperature determined by data from a second temperature sensor TE that may be located in cooling discharge duct 4b or cooling flow discharge outlet 4bo). When the difference between the inlet and outlet temperatures, determined by data received from the first and second temperature sensors, is within a pre-selected pump operating temperature threshold (e.g., within 200℉ or 115°C, 100℉ or 60°C, 50℉ or 30°C, or another suitable range), and the pump temperature is also determined to be equal to or lower than a pre-selected operating temperature (e.g., the first temperature sensor TE of the pump provides measurement data indicating that the pump temperature is equal to or lower than -200℉, equal to or lower than -300℉, equal to or lower than -350℉, equal to or lower than 400℉, equal to or lower than 240°C, equal to or lower than -180°C, etc.), it can be determined that pump 5 is at the desired operating temperature for operation. This temperature verification process can be performed after the controller CTRL determines that there is a demand for liquid hydrogen at one or more distributors 9, thus making it desired to start pump 5.

[0084] In response to this determination, the controller CTRL can communicate with other components to regulate valve 4acv of the hydrogen feed pipeline assembly 4 and other units of the actuation equipment. For example, after the pump operating temperature conditions are met, the cooling operation can be stopped by closing valve 4acv, which is used to vent the pipeline assembly 4, and the pump drive motor can be turned on so that pump 5 can start driving liquid hydrogen 3L to flow out of storage tank 3 through pump 5 and through pump discharge outlet 4do and pump discharge pipe 4d, for feeding liquid hydrogen from storage tank 3 to FCM7 and distributor 9 under increased pressure.

[0085] The controller CTRL can send communications to the valve and pump 5 to automatically control the operation, or the controller CTRL can be configured to display a flag related to the detected condition to the operator via a display communicatively connected to the controller CTRL, thereby facilitating the operator to provide input using input devices to initiate valve regulation and start the pump drive motor. In response to receiving this input, the controller CTRL can then send communications for regulating the valve and starting the pump drive motor, thereby satisfying the liquid hydrogen demand at one or more distributors by feeding liquid hydrogen from the pump to the distributors.

[0086] For example, in response to determining (i) a demand for liquid hydrogen at distributor 9, (ii) a difference within a pre-selected pump operating temperature threshold, and (iii) a pump temperature indication via pump temperature sensor TE indicating that the pump is at a temperature equal to or below the pre-selected operating temperature threshold, controller CTRL can send communication to close the valve of cooling discharge line 4b to stop hydrogen discharge, and activate the pump drive motor to activate pump 5 to move the piston 5p of pump 5 within compression chamber 5cav to feed hydrogen from storage tank 3 to one or more distributors 9. These communications can be sent automatically or upon receiving operator input.

[0087] After performing a cooling operation to meet the liquid hydrogen demand at distributor 9, checking whether pump 5 is at the desired operating temperature for pump startup can be adapted to meet multiple different design criteria. In some embodiments, the distal measuring point 5tp of temperature sensor TE can be located at a pre-selected detection location LDS within the pump. For vertical pumps, such as Figure 4 The pump 5 shown can be positioned at a pre-selected detection location LDS adjacent to the bottom 5btm of the pump cylinder below the main feed inlet 5fi of the compression chamber 5cav. For horizontal pumps, such as Figure 3 The pump 5 shown has a pre-selected detection position LDS that can be positioned adjacent to the bottom 5btm side of the pump via a weir plate 5wp located near the main feed inlet 5fi, which is in fluid communication with the compression chamber 5cav. The weir plate 5wp can also be considered as a weir baffle or other type of element within the pump, which can be used to generate a known level-flow relationship. A distal measuring point 5tp can be positioned behind the weir plate 5wp, such that the weir plate 5wp is located between the measuring point 5tp of the temperature sensor TE within the pump 5 and the piston 5p located in the compression chamber 5cav.

[0088] In an embodiment of pump 5 that utilizes liquid hydrogen for cooling, the location of the remote measuring point 5tp can be positioned such that the sensor measures the temperature of the liquid hydrogen accumulated at the pre-selected detection location LDS due to the cooling operation flow of hydrogen. For example, this detection can occur by measuring the hydrogen temperature related to the temperature of the liquid cryogenic hydrogen within the storage tank 3 using the temperature sensor TE (e.g., -423℉, -253℃, -400℉, -240℃, or temperatures between -423℃ and -350℉, or between -253℃ and -180℃, depending on the calibration of the temperature sensor TE according to the pump's operating conditions, etc.). Once this detection occurs, it can be determined that the cooling operation has adequately cooled pump 5, and the pump can be started.

[0089] After pump 5 is adequately cooled and pump operation begins, one or more valves in the cooling discharge pipe 4b can be adjusted so that any hydrogen (e.g., hydrogen gas) that may pass through piston ring 5pr during pump 5 operation can be discharged from cooling flow discharge outlet 4bo and fed back to storage tank 3 (instead of being discharged), as described above.

[0090] When the pump is operating, the hydrogen received by pump 5 via pump feed inlet 5a can be compressed and subsequently discharged from pump 5 via pump discharge pipe 4d. After being discharged from pump 5, the liquid hydrogen can be heated in heat exchanger 6 and then fed to FCM 7 via FCM feed pipe 4e. The heating medium can pass through heat exchanger 6 in a co-current or counter-current manner to facilitate heating of the hydrogen passing through heat exchanger 6. The hydrogen can then be transferred from FCM to one or more distributors 9.

[0091] When hydrogen demand at one or more distributors 9 is low or ceases, pump operation can be stopped (e.g., pump can be deactivated). Pump 5 may be shut down for extended periods and will become hot during shutdown due to the lack of cryogenic hydrogen passing through it. In the event that pump 5 is restarted due to another increase in hydrogen demand at one or more distributors 9, a cooling operation can be performed again before the pump drive motor is actuated to ensure that pump 5 is at the desired operating temperature before being turned on to feed hydrogen to FCM7 and one or more distributors 9. Each time pump 5 is started (or restarted) to allow hydrogen to flow to FCM7 and distributors 9, a cooling operation can be performed before starting the pump drive motor.

[0092] Embodiments of pump cooling operation that utilize pump 5 and the equipment for cooling pump 5 allow pump 5 to be cooled to the desired operating temperature without venting downstream piping or allowing hydrogen product to flow through pump 5 into the atmosphere via hydrogen bypass 6a and exhaust 4f. However, the downstream exhaust 4f, in fluid communication with bypass 6a, may be retained in the equipment embodiment to provide maintenance or emergency venting capabilities, thereby addressing various problems that may arise during operation.

[0093] The embodiment of pump cooling operation utilizing pump 5 and the equipment for cooling pump 5 allows pump 5 to be cooled to the desired operating temperature without requiring the pump to be submerged in cryogenic liquid hydrogen or always having liquid hydrogen flowing through the pump during continuous operation. This improves energy efficiency by avoiding continuous pump operation and avoids the higher costs and maintenance issues associated with continuous pump submersion, continuous pump operation, or product flowing through the pump when not needed. For example, such pump submersion schemes can lead to significant losses due to the substantial hydrogen evaporation that occurs when the pump is kept submerged. In contrast to the pump submersion method, we believe that our equipment and pump cooling method embodiments can avoid the significant hydrogen losses that can occur due to pump submersion when the pump is not operating.

[0094] The embodiment of pump cooling operation using the pump 5 and the embodiment of the equipment for cooling the pump 5 can allow the pump 5 to reduce hydrogen loss by reducing the volume of hydrogen discharged for pump cooling, facilitate faster pump start-up time by pressurizing the discharge line to reduce hydrogen loss and reduce pump start-up time, allow faster pump start-up time to directly refuel vehicles at the distributor 9 while also helping to minimize the need for gas storage or secondary pre-cooling systems for refueling stations, and can also provide effective cooling by allowing hydrogen to flow along the cooling hydrogen discharge path inside the pump.

[0095] We conducted covert experiments and simulations of our pump cooling operation using embodiments of our pump 5 and the equipment used to cool pump 5, and found that in some cases, the start-up time can be less than two minutes (e.g., less than 30 seconds, less than 15 seconds, less than 5 seconds, between 5 seconds and two minutes, etc.), while in other extreme temperatures where the pump may have been heated to a higher ambient temperature, the start-up time can be in the range of 2-5 minutes. Under other temperature conditions, for different experiments using different embodiments and different pump start-up temperatures, pump 5 was able to be adequately cooled in cooling times of less than 20 minutes, in the range of 4-7 minutes, and less than 5 minutes. Furthermore, hydrogen loss can be reduced by more than 50% compared to conventional cooling operations, which can provide a significant operational improvement in reducing hydrogen loss.

[0096] It should be understood that embodiments of the equipment for cooling pumps can be positioned and configured to facilitate hydrogen fuel distribution and / or storage. Pump cooling equipment for cryogenic operation of pumps, embodiments of our pump cooling operation before the pump drive motor is started, and methods of manufacture and use thereof can be configured to include process control elements positioned and configured to monitor and control operation (e.g., temperature and pressure sensors, flow sensors, automated process control systems having at least one workstation including a processor, non-transitory memory, and at least one transceiver for communicating with sensor elements, valves, and controllers for providing a user interface for an automated process control system that can operate at the workstation and / or equipment).

[0097] Some exemplary embodiments discussed herein relate to the use of hydrogen. Hydrogen is an example of a cryogenic fluid. Other embodiments of pump 5 may be used with other types of cryogenic fluids (e.g., cryogenic liquids and / or cryogenic gases) instead of hydrogen and / or liquid hydrogen. For example, storage tank 3 may hold another type of cryogenic fluid (e.g., cryogenic helium, cryogenic nitrogen, or cryogenic oxygen). In such embodiments, pump discharge conduit 4d may feed the pumped liquid to plant components for subsequent use, rather than to FCM 7 and / or distributor 9. For such embodiments, liquid feed conduit 4a may be considered as cryogenic liquid feed conduit 4a. In such embodiments, the demand at distributor 9 may not be a criterion for starting pump 5 via controller CTRL. Instead, other control criteria (e.g., the demand of plant components or air separation unit components for cryogenic liquids or cryogenic fluids, etc.) may be involved in addition to the operating temperature assessment criterion. Therefore, it should be understood that the exemplary embodiment of a hydrogen refueling station is one example, and other embodiments and uses may be considered in addition to use in hydrogen refueling station type environments. The embodiments can be alternatively used in air separation units, air separation plants, or other industrial plants that may utilize one or more cryogenic liquids or fluids (e.g., cryogenic oxygen, cryogenic nitrogen, cryogenic helium, etc.). The cooling paths for pump cooling operations discussed above with reference to hydrogen and / or liquid hydrogen can involve using different cryogenic gases and cryogenic liquids that pass through the flow paths along these embodiments. For example, in such embodiments, the cryogenic gas may be cryogenic nitrogen, oxygen, or helium, instead of hydrogen. In such embodiments, the cryogenic liquid used via the pump may pass through and discharge liquid hydrogen along the same flow path as described above. However, this cryogenic liquid may be delivered to a different type of downstream unit instead of FCM7 and distributor 9.

[0098] In such embodiments, the pre-selected temperature and pressure of storage tank 3 can vary to accommodate different cryogenic fluids (e.g., the temperature can be below the fluid's boiling point, thus keeping the fluid liquid). For example, for the storage and pumping of liquid helium, the pre-selected storage temperature could be below or equal to -269°C. For embodiments where the cryogenic fluid is cryogenic nitrogen, the pre-selected storage temperature could be below or equal to -196°C. For embodiments where the cryogenic fluid is argon, the pre-selected storage temperature could be at least -186°C. For embodiments where the cryogenic fluid is oxygen, the pre-selected storage temperature could be below or equal to -182°C.

[0099] It should also be understood that other modifications can be made to the embodiments explicitly shown and discussed herein to meet a specific set of design goals or a specific set of design criteria. For example, components of valves, piping systems, and other piping elements (e.g., pipe connections, tubing, seals, etc.) used for fluid communication between different units of an interconnecting device to allow fluid flow between the different units can be arranged to meet a specific layout design that takes into account the available area of ​​the hydrogen fuel distribution and / or storage system, the system's equipment size, and other design considerations. As another example, the flow rate, pressure, and temperature of fluids through different components of the device and through other device components can be varied to account for different cryogenic fluid storage and use system design configurations and other design criteria. As yet another example, the material composition of the different structural components of the device can be any type of suitable material that may be required to meet a specific set of design criteria.

[0100] As another example, it is contemplated that specific features described individually or as part of an embodiment can be combined with other individually described features or portions of other embodiments. Therefore, elements and actions of the various embodiments described herein can be combined to provide further embodiments. Thus, although certain exemplary embodiments of our devices for hydrogen storage and distribution, devices for cooling pumps (which can be positioned and configured to facilitate hydrogen fuel distribution), pump cooling devices for cryogenic operation of pumps, cryogenic pumps, and methods of manufacturing and using them have been shown and described above, it should be clearly understood that the invention is not limited thereto, but can be practiced and implemented in other ways within the scope of the following claims.

Claims

1. An apparatus for hydrogen storage and distribution, comprising: A pump, configured to receive hydrogen from at least one storage tank; The pump has a pump discharge outlet for a pump discharge pipe through which liquid can flow out of the pump; The pump also has a compression chamber and a movable piston that can move within the compression chamber, and the pump also has piston rings positioned near the compression chamber and the movable piston; The piston rings and the compression chamber are positioned and configured such that hydrogen can flow into the compression chamber when the piston is stationary, and can flow from the compression chamber through the piston rings to a cooling outlet, the cooling outlet being configured to be in fluid communication with a cooling discharge conduit for discharging the hydrogen to the atmosphere. The at least one storage tank; A hydrogen feed pipeline assembly, comprising at least one of a liquid feed pipeline and a hydrogen supply pipeline, the liquid feed pipeline being connected between the at least one storage tank and the feed inlet of the pump to supply liquid hydrogen from the at least one storage tank to the pump, and the hydrogen supply pipeline being connected between the at least one storage tank and the feed inlet of the pump to supply hydrogen from the at least one storage tank to the pump. The cooling exhaust pipe is connected to the pump, so that hydrogen flowing through the cooling outlet can exit the pump and pass through the cooling exhaust pipe to be discharged during the pump's cooling operation; The cooling discharge pipe has an adjustable valve that can be adjusted to an open position to discharge hydrogen during the cooling operation of the pump when the pump is stopped. A first temperature sensor is connected to the pump to measure the temperature of hydrogen fed from the at least one storage tank to the pump; A second temperature sensor is connected to the cooling discharge pipe to monitor the temperature of the hydrogen output from the pump to flow through the cooling discharge pipe; as well as A controller, communicatively connected to the first temperature sensor and the second temperature sensor, is used to determine the difference between the temperature of hydrogen fed from the at least one storage tank to the pump and the temperature of hydrogen discharged from the pump and flowing through the cooling discharge pipe; The controller is configured to determine that the pump is at a temperature within a pre-selected operating temperature range, and in response to determining that the difference is within a pre-selected pump operating temperature threshold, to determine that the pump can be started to feed hydrogen to the distributor.

2. The apparatus for hydrogen storage and distribution according to claim 1, wherein the controller is configured to regulate the valves of the hydrogen feed pipeline assembly and communicate with the pump drive motor to turn on the pump in response to determining that the pump is at a temperature within the preselected pump operating temperature threshold and that the difference is within the preselected pump operating temperature threshold.

3. The apparatus for hydrogen storage and distribution according to claim 1, wherein the pump includes an internal cooling channel positioned to allow a portion of the hydrogen to flow to an internal pump component after the hydrogen has flowed through the piston, while moving along a cooling flow path toward the cooling flow outlet.

4. The apparatus for hydrogen storage and distribution according to claim 3, wherein the internal cooling passage is defined within the cylinder of the pump.

5. A method for performing a pump cooling operation, comprising: Open the valve of the cooling discharge pipe, which is connected to a pump in fluid communication with the storage tank, so that when the pump is stopped, hydrogen in the storage tank can flow into the compression chamber of the pump; When the piston of the pump is stationary, the hydrogen is allowed to flow out of the storage tank and into the pump, thereby causing the hydrogen that flows into the compression chamber when the piston is stationary to flow out of the compression chamber and pass through the piston rings positioned near the compression chamber and the piston; The hydrogen gas is circulated from the piston to the cooling discharge pipe for discharge. The temperature of hydrogen flowing through a portion of the pump is monitored to measure the temperature of hydrogen fed from the storage tank to the pump, wherein a first temperature sensor connected to the pump measures the temperature of hydrogen flowing through a portion of the pump; The temperature of hydrogen flowing from the pump through the cooling discharge pipe is monitored, wherein a second temperature sensor connected to the cooling discharge pipe measures the temperature of the hydrogen flowing from the pump through the cooling discharge pipe; A controller communicatively connected to the first and second temperature sensors determines whether the pump is at or below a pre-selected pump operating temperature threshold. as well as In response to determining that the pump is at or below the pre-selected pump operating temperature threshold, the controller sends a communication to close the valve of the cooling discharge pipe to stop the discharge of hydrogen.

6. The method of claim 5, further comprising: The pump is determined to be cooled to a temperature within a pre-selected operating pump temperature range; as well as In response to determining that the pump is at a temperature within the pre-selected operating pump temperature range and that there is a demand for liquid hydrogen at a distributor connected to the pump, the valve of the cooling discharge pipe is closed to stop the discharge of hydrogen, and the pump drive motor is turned on to start the pump for moving the piston of the pump within the compression chamber to feed liquid hydrogen from the storage tank to at least one distributor.

7. The method of claim 5, further comprising: Determine the difference between the temperature of the hydrogen flowing through the pump and the temperature of the hydrogen exiting the pump and flowing through the cooling discharge pipe; as well as In response to determining that (i) the difference is within a pre-selected pump operating temperature threshold, (ii) the temperature of the hydrogen flowing through the pump is within a pre-selected pump operating temperature range, and (iii) there is a demand for liquid hydrogen at a distributor fluidly connected to the pump, the valve of the cooling discharge pipe is closed to stop the discharge of the hydrogen, and the pump drive motor is turned on to start the pump for moving the piston of the pump within the compression chamber to feed liquid hydrogen from the tank to the distributor.

8. The method of claim 5, further comprising: In response to determining that the temperature inside the pump is within the pre-selected operating temperature range, the valve of the cooling discharge pipe is closed to stop the discharge of hydrogen, and the pump drive motor is turned on to start the pump, so as to move the piston of the pump within the compression chamber to feed liquid hydrogen from the storage tank to a distributor fluidly connected to the pump.

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