Patent Application
20240295292
When hydrogen powered vehicles or machines are refueled, hydrogen gas is transferred from a high-pressure storage vessel to a receiving vessel or a vessel in the vehicle or machine. The addition of the gas into the receiving vessel compresses the gas in the receiving vessel leading to an increase in temperature. For fast refueling, the fast addition of gas to the receiving vessel leads to rapid compression of the gas in the receiving vessel causing high gas temperatures in that vessel because there is insufficient time for the heat generated during the compression to dissipate through the vessel walls. High temperatures of the gas in the receiving vessel can lead to a weakening or damage in the receiving vessel wall. Thus, the lifetime of the receiving vessel is reduced by high gas temperatures in the receiving vessel. For example, if the receiving vessel is a light-weight composite cylinder, such cylinders can be damaged if the temperature of the gas within the cylinder exceeds 85° C. Additionally, over time, the high temperature of the gas in the receiving vessel will reduce until it reaches an equilibrium state with the cooler temperature of the ambient surroundings. Thus, the gas pressure in the receiving vessel is reduced and hence the mass of gas stored in the receiving vessel is lower than its maximum capacity.
To avoid high gas temperatures in the receiving vessel, the rate of gas addition into the vessel may be limited. This may be achieved by filling the receiving vessel in stages, by adding an amount of gas to the receiving vessel then waiting for the heat generated from the gas transfer to dissipate through the vessel wall and from the vessel exterior surface through conduction, convection or radiation. Once the heat has sufficiently dissipated more gas can be added to the receiving vessel. This process leads to a slow rate of refueling.
Alternatively, the hydrogen gas may be cooled prior to being transferred to the receiving vessel. Typically, the gas may be cooled to between 0° C. and −40° C. prior to transfer into the receiving vessel. This allows for fast refueling of hydrogen powered vehicles or machines. A refrigeration cycle may be used to cool the hydrogen through a heat exchanger. However, chilling hydrogen in this way is energy-intensive given the high specific heat capacity of hydrogen of 14.3 kJ/kgK. Such problems are not unique to hydrogen gas and may also be associated with other compressed gases.
It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art. In particular, the invention provides a method and apparatus for improving the cooling of a gas during transfer to a receiving vessel.
According to a first aspect of the invention, there is provided a method of transferring gas. The method comprises:
In certain embodiments, expanding the process gas may comprise expanding a portion of the process gas into the receiving vessel to produce the first volume residing in the receiving vessel.
The method may comprise expanding a first gas having a fourth temperature that is greater than the first temperature to produce a first volume of the first gas and a second volume of the first gas that has the first temperature, wherein process gas comprises the first volume of the first gas.
The method may comprise storing the second volume of the process gas in a vessel prior to displacing at least some of the second volume of the process gas into the receiving vessel using the piston gas, wherein the vessel is thermally insulated from a surrounding environment or the vessel is thermally insulated from the second volume of the process gas.
In certain embodiments, the second volume of the process gas may have substantially the same pressure as the receiving vessel.
The method may comprise providing the process gas by displacing a first gas wherein the first gas and the process gas are at substantially the same pressure.
In certain embodiments, at least some of the first volume of the process gas may be cooled prior to it residing in the receiving vessel or a vessel. The method may comprise using a heat exchanger to cool the at least some of the first volume of the process gas prior to it residing in the receiving vessel or the vessel.
In certain embodiments, displacing the at least some of the second volume of the process gas into the receiving vessel using the piston gas may comprise using the piston gas to cause the at least some of the second volume of the process gas to substantially flow according to a plug flow regime into the receiving vessel thereby minimising axial transfer of heat between the first and second volumes of process gas.
A series of elongate members may be provided along which the at least some of the second volume of the process gas is caused to flow such that radial flow is inhibited.
A float may be provided in the series of elongate members between the process gas and the piston gas.
The series of elongate members may comprise a bundle of elongate members. The series elongate members may comprise a series of elongate members that tessellate with one another.
The process gas and the piston gas may each be a compressed gas. The compressed gas may comprise one of oxygen, nitrogen, argon, helium, hydrogen, compressed natural gas, methane and mixtures thereof.
According to a second aspect of the invention, there is provided an apparatus for transferring gas to a receiving vessel. The apparatus comprises:
In certain embodiments, the first vessel may be configured to be thermally insulated from a surrounding environment or from a volume of gas within the first vessel.
The second vessel may be thermally coupled to a heat exchanger that is arranged to remove heat from a volume of gas when the volume of gas is contained in the second vessel.
The second vessel may be selectively fluidly connectable to the auxiliary vessel such that the auxiliary gas may flow from the auxiliary vessel into the second vessel without passing through the first vessel and wherein the second vessel comprises an opening selectively fluidly connectable to a receiving vessel.
The apparatus may comprise a heat exchanger in a fluid path connecting the first and second vessels. The heat exchanger may be configured to cool to gas to ambient air temperature.
The apparatus may comprise a third vessel and a fourth vessel; wherein the third vessel and the fourth vessel each comprise an opening selectively fluidly connectable to the receiving vessel; wherein the first, second, third and fourth vessels are each selectively fluidly connectable to the auxiliary vessel such that the auxiliary gas may flow from the auxiliary vessel into each of the vessel without passing through another vessel; and wherein the first and fourth vessels, the second and third vessels and the third and fourth vessels are selectively fluidly connectable coupled to each other
The apparatus may comprise at least one heat exchanger arranged to remove heat from a volume of gas flowing between at least two of the first, the second, the third and the fourth vessels.
The at least one heat exchanger may be configured to cool the volume of gas to ambient air temperature.
The apparatus may comprise a first series of elongate members within the first vessel.
The apparatus may comprise a second series of elongate members within the second vessel.
The apparatus may comprise a first series of elongate members within the first vessel, a second series of elongate members within the second vessel, a third series of elongate members within the third vessel and a fourth series of elongate members within the fourth vessel.
The apparatus may comprise a float movable within each series of elongate members.
Each series of elongate members may comprise a bundle of elongate members. Each series elongate members may comprise a series of elongate members that tessellate with one another.
Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:
The apparatus 10 comprises an auxiliary vessel 11, an intermediate vessel 12 and a receiving vessel 13. Each vessel 11, 12, 13 is configured to receive and store gas. The intermediate vessel 12 comprises an inlet or first opening 14. The auxiliary vessel 11 is selectively fluidly connectable to the inlet 14 of the intermediate vessel 12 such that a fluid path 15 selectively connects the auxiliary vessel 11 and the intermediate vessel 12. The intermediate vessel 12 comprises an outlet or second opening 16. The outlet 16 is selectively fluidly connectable to the receiving vessel 13 such that a fluid path 17 selectively connects the intermediate vessel 12 and the receiving vessel 13. The apparatus 10 may comprise values 18, 19 for controlling gas flow along the fluid path 15 connecting the auxiliary and intermediate vessels 11, 12 and the fluid path 17 connecting the intermediate and receiving vessels 12, 13. The valves 18, 19 may comprise needle valves or any other valve capable of controlling the flow of gas along a fluid path. The apparatus 10 may be configured so that each of the auxiliary vessel 11 and the receiving vessel 13 can be disconnected from the intermediate vessel 12. Thus, during use, the auxiliary vessel 11 and/or the receiving vessel 13 are replaceable in the apparatus 10. The auxiliary vessel 11 may be a high-pressure storage vessel having a large volume compared to the intermediate vessel 12. The receiving vessel 13 may have a larger volume that the intermediate vessel 12. The receiving vessel 13 may comprise a fuel tank within a vehicle or a machine. However, the method is not limited to such receiving vessels 13.
The apparatus 10 may be used when implementing the method of transferring a gas shown in
Before gas is transferred using the method of
The first step 1 of the method comprises expanding the process gas to produce a first volume of the process gas and a second volume of the process gas. The first volume of the process gas has a second temperature that is greater than the first temperature. The second volume of the process gas has a third temperature that is less than the first temperature.
The process gas may be expanded in the apparatus 10 of
During the first step 1 of the method, the temperature of the gas already present in the receiving vessel 13 increases. This is because the process gas which expands into the receiving vessel 13 compresses the gas already present in the receiving vessel 13 increasing its temperature.
The first step 1 of the method ends when the gas in the intermediate vessel 12 and receiving vessel 13 are at substantially the same pressure. The temperature in the intermediate vessel 12 has decreased during the first step 1 of the method and the temperature of the receiving vessel 13 has increased during the first step 1 of the method.
The second step 2 of the method comprises displacing at least some of the second volume of process gas into the receiving vessel 13 using a piston gas. In the apparatus 10 of
The second step 2 of the method ends once a sufficient amount of the second volume of process gas has been displaced into the receiving vessel 13. When this occurs, the valve 18 on the fluid path 17 connecting the intermediate 12 and receiving 13 vessels is closed. The valve 18 may be closed once all or only a portion of the second volume of process gas has been displaced into the receiving vessel. If a portion of the second volume of process gas remains within the intermediate vessel after the valve 18 has closed, this portion of the second volume mixes with the piston gas which entered the intermediate vessel 12. The mixing at least partly counteracts the increase in the temperature of the piston gas that was caused when the piston gas entered the intermediate vessel 12.
During the second step 2 of the method, the piston gas increases the pressure within the intermediate vessel 12. Therefore, at the end of the second step 2 of the method the pressure within the intermediate vessel 12 may be greater than the pressure in the receiving vessel 13. Thus, the method can be repeated to transfer additional gas into the receiving vessel 13. In certain embodiments, the valve 19 on the fluid path 15 between the auxiliary vessel 11 and the intermediate vessel 12 may remain open after the valve 18 on the fluid path connecting the intermediate vessel 12 and the receiving vessel 13 is closed at the end of the second step 2 of the method. Thus, the pressure in the intermediate vessel 12 may be increased further before repeating the first 1 and second 2 method steps. The auxiliary vessel 11 and intermediate vessel 12 may be allowed reached substantially the same pressure before repeating the first 1 and second 2 method steps.
The above described method enables gas to be transferred into a receiving vessel 13, increasing the pressure in the receiving vessel. However, the increase in temperature of the receiving vessel 13 due to this transfer is limited due to the cooling of the second volume of process gas prior to displacing said volume into the receiving vessel 13. At the end of the second step 2 of the method, the first volume of gas with the second temperature and at least some of the second volume of process gas having the third temperature reside in the receiving vessel 13. These gases mix within the receiving vessel 13 so that the final temperature of the process gas within the receiving vessel 13 is less than the second temperature. If substantially all the second volume of process gas is displaced into the receiving vessel 13 the final temperature of the process gas within the receiving vessel 13 may be further reduced. The method therefore enables the temperature of gas within a receiving vessel 13 to be controlled. Additionally, since a gas is used as a piston this reduces the number of moving parts required in the apparatus 10 for transferring gas, thus reducing costs associated with and maintenance of such an apparatus for transferring gas.
In the second step 2 of the method, the piston gas may cause at least some of the second volume of the process gas to substantially flow according to a plug flow regime into the receiving vessel 13. A plug flow regime is one in which there is minimal radial mixing and axial dispersion between two flowing gases i.e. between the piston gas and the second volume of the process gas. Thus, a plug flow regime reduces axial transfer of heat between the piston gas and the second volume of process gas. This is advantageous in that it further limits the temperature increase in the receiving vessel when transferring gas. In the first step 1 of the method, the second volume of process gas was cooled to the third temperature, and as the piston gas displaces the second volume of process gas in the second step 2, the temperature of the piston gas increases. Therefore, it is advantageous to use a plug flow regime in order to limit the heat transfer from the warmer piston gas to the cooler second volume of process gas which enters the receiving vessel 13.
To facilitate the plug flow regime, the method may comprise providing a series of elongate members along which the at least some of the second volume of the first process gas is caused to flow such that radial flow is inhibited. Since the elongate members are narrow relative to their length, radial flow between the piston gas and the second volume of process gas is limited thereby reducing axial transfer of heat between the piston gas and the second volume of process gas. The series of elongate members (not shown) may be incorporated in the apparatus 10 of
The series of elongate members may be arranged end-to-end to form a single passage through which gas can flow. Alternatively, the series of elongate members may comprise a bundle of elongate members. That is, the elongate members may be arranged side-by-side so that gas can flow through parallel elongate members. In some embodiments, the series of elongate members may comprise a series of tubular members. When the series of elongate members comprises a bundle of tubular elongate members, gas flows through both the tubular members and spaces formed between the tubular members. In alternative embodiments, each elongate member in the series of elongate members may be shaped such that the elongate members tessellate with one another. For example, all elongate members in the series may have the same shape cross-section and each elongate member in the series may, for example, be a hexagon, quadrilateral, triangle or another tessellating shape in cross-section. This is advantageous when the series of elongate members comprises a bundle because the elongate members provide conduits through which gas can flow which are all the same size. Thus, the pressure across the bundle of elongate members may be substantially uniform.
In certain embodiments, the method may comprise providing one or more floats in the series of elongate members so that in the second step 2 of the method the floats reside between the process gas and the piston gas. The apparatus 10 may comprise one or more floats (not shown) within the series of elongate members. As the piston gas displaces the second volume of process gas, the float moves through the series of elongate members at the boundary between the two gases. Thus, the float reduces mixing between the piston gas and the process gas further improving the plug flow regime. The float may extend across at least part of the cross-section of the series of elongate members to allow gas to pass around the edges of float whilst limiting mixing of the process and piston gases. In embodiments where the series of elongate members comprises a bundle of elongate members, each elongate member in the bundle may comprise a float. In certain embodiments, the float may be a rotameter float. The float may be a sphere, disk or the cross-section of the float may be the same shape as the cross section of the elongate member in which the float resides.
The apparatus 10 may comprise an injector (not shown) at the inlet 14 of the intermediate vessel. The injector injects gas that flows along the fluid path 15 connecting the auxiliary vessel 11 and the intermediate vessel 12 into the intermediate vessel. The injector may be configured to facilitate the plug flow regime of the piston gas by reducing the velocity at which the piston gas enters the intermediate vessel 12. Thus, reducing radial mixing and axial dispersion between the piston gas and the second volume of the process gas. In certain embodiments, the injector may comprise a U-bend so the piston gas entering the intermediate vessel 12 is directed back on itself. The intermediate vessel 12 may additionally or alternatively comprise a plate onto which the piston gas is directed thereby further slowing the velocity of the gas. In certain embodiments, the injector may comprise a conduit which extends into the intermediate vessel 12 from the inlet 14. The piston gas may flow into the intermediate vessel 12 through the conduit. The diameter of the conduit may increase in a direction away from the inlet 14. This increase in diameter causes the velocity of the piston gas to decrease as the gas flows along the conduit facilitating a plug flow regime in the intermediate vessel 12.
The apparatus 110 comprises an auxiliary vessel 111, two intermediate vessels and a receiving vessel 113. The two intermediate vessels comprise a first vessel 121 and a second vessel 122. Each vessel in the apparatus 110 is configured to receive and store gas. The first vessel 121 comprises a first opening 123. The auxiliary vessel 111 is selectively fluidly connectable to the first opening 123 of the first vessel 121 such that a fluid path 124 selectively connects the auxiliary vessel 111 and the first vessel 121. The first vessel 121 is selectively fluidly connectable to the auxiliary vessel 111 such that gas may flow from the auxiliary vessel 111 into the first vessel 121 without passing through the second vessel 122. As shown in
The first vessel 121 comprises a second opening 127 that is fluidly connected to a corresponding opening 128 in the second vessel 122 so that there is a fluid path 129 selectively connecting the first vessel 121 and the second vessel 122. Along this fluid path 129, gas can flow both from the first vessel 121 to the second vessel 122 and from the second vessel 122 to the first vessel 121. In alternative embodiments, two fluid paths may selectively connect the first and second vessels 121, 122 such that gas may flow from the first vessel 121 to the second vessel 122 along one of the fluid paths and gas may flow from the second vessel 122 to the first vessel 121 along the other fluid path.
The apparatus 110 may comprise one or more valves 130, 131, 132 for controlling gas flow along fluid paths 124, 126, 129. The apparatus 110 may comprise a first valve 130 along the fluid path 124 connecting the auxiliary vessel 111 and the first vessel 121, a second valve 131 along the fluid path 129 connecting the first vessel 121 and the second vessel 122 and a third valve 132 along the fluid path 126 connecting the first vessel 121 and the receiving vessel 112. The valves 130, 131, 132 may comprise needle valves or any other valve suitable of controlling the flow of gas along a fluid path. In alternative embodiments, the first valve 130 and the second valve 131 may be replaced by single valve configured to control the flow of gas between the first vessel 121 and both the auxiliary vessel 111 and the receiving vessel 113.
The apparatus 110 may be configured so that each of the auxiliary vessel 111 and the receiving vessel 113 can be disconnected from one or both of the intermediate vessels 121, 122. Thus, during use, the auxiliary vessel 111 and/or the receiving vessel 113 may be replaceable in the apparatus 110.
The auxiliary vessel 111 may be a high-pressure storage vessel having a large volume compared to the first vessel 121 and the second vessel 122. The first and second vessels 121, 122 may have substantially the same volume as one another. The receiving vessel 113 may have a larger volume than the first vessel 121 and/or the second vessel 122. In certain embodiments, the receiving vessel 113 may comprise a fuel tank within a vehicle or a machine. However, the method is not limited to such receiving vessels 113.
The apparatus 110 of
The first step 103 of the method comprises expanding the first gas to produce a process gas. This is done by expanding the first gas to provide a first volume of the first gas and a second volume of the first gas. The first gas is expanded in the apparatus 110 by opening the valve 131 on the fluid path 129 connecting the first vessel 121 and the second vessel 122 so that the first gas expands into the second vessel 122. Thus, at the end of the first step 103 of the method, the first volume of the first gas resides in the second vessel 122 and the second volume of the first gas resides in the first vessel 121.
In the same manner as described for the embodiment of
The portion of the first gas which expands within the first vessel 121 to form the second volume of first gas expands substantially isentropically which leads to the temperature of the first gas residing in the first vessel 121 decreasing. During the first step 103 of the method, the portion of the first gas in the first vessel 121 decreases from the fourth temperature to a first temperature.
The first step 103 of the method ends when the first and second volumes of process gas are at substantially the same pressure. Thus, the pressure in the second vessel 122 has increased and the pressure in the first vessel 121 has decreased during the first step 103 of the method. At this point, the pressure in both the first vessel 121 and the second vessel 122 is greater than the pressure in the receiving vessel 113. At the end of the first method step 103, the valve 131 between the first vessel 121 and the second vessel 122 is closed.
The second step 101 of the method comprises expanding a process gas to produce a first volume of the process gas and a second volume of the process gas. In the apparatus 110 of
The process gas may be expanded in the apparatus 110 by opening the valve 132 on the fluid path 126 connecting the first vessel 121 and the receiving vessel 113. Since the process gas initially contained in the first vessel 121 is at a higher pressure than the gas in the receiving vessel 113, a portion of process gas expands into the receiving vessel 113. This portion of process gas compresses the gas already present in the receiving vessel 113, increasing the temperature of process gas in the receiving vessel 113. The process gas received in the receiving vessel 113 comprises the first volume of the process gas having the second temperature. At least some of the process gas remains in the first vessel 121 and expands substantially isentropically within the first vessel 121 which leads to a decrease in temperature of the process gas in the intermediate vessel 121. The process gas which remains in the first vessel 121 comprises the second volume of process gas having the third temperature.
The second step 101 of the method ends when the gas in the first vessel 121 and receiving vessel 113 are at substantially the same pressure. The temperature in the first vessel 121 has decreased again during the second step 101 of the method. Since the receiving vessel 113 now contains the first volume of process gas, the temperature of the receiving vessel 113 has increased during the second step 101 of the method.
At the end of the second step 101 of the method, the first and second volumes of process gas are at substantially the same pressure. Thus, the pressure in the first vessel 121 has decreased during the second step 101 and is now lower than the pressure in the second vessel 122. Consequently, the first volume of the first gas residing in the second vessel 122 can act as the piston gas in accordance with the method of
The third step 102 of the method comprises displacing at least some of the second volume of process gas into the receiving vessel 113 using the piston gas. The second volume of process gas may be displaced from the first vessel 121 by opening the valve 131 on the fluid path 129 connecting the first vessel 121 and the second vessel 122. The piston gas (i.e. the first volume of the first gas) in the second vessel 122 has a higher pressure than the second volume of process gas in the first vessel 121, and the piston gas flows along the fluid path 129 into the first vessel 121. In the same manner as described for
During the third step 102 of the method, the valve 132 on the fluid path 126 connecting the first vessel 121 and the receiving vessel 113 remains open so that the second volume of process gas which is displaced from the first vessel 121 is received by the receiving vessel 113. The second volume of process gas enters the receiving vessel 113 substantially isobarically because at the end of the second step 101 of the method the first vessel 121 and receiving vessel 113 are at substantially the same pressure. Thus, the increase in temperature in the receiving vessel 113 caused by the second volume of process gas is minimised.
The third step 102 of the method ends once a sufficient amount of the second volume of process gas has been displaced into the receiving vessel 113. When this occurs, the valve 132 on the fluid path 126 connecting the first vessel 121 and the receiving vessel 113 is closed. The valve 132 may be closed once all or only a portion of the second volume of process gas has been displaced into the receiving vessel 113. If a portion of the second volume of process gas remains within the first vessel 121 after the valve 132 has closed, this portion of the second volume mixes with the piston gas which entered the first vessel 121. The mixing at least partly counteracts the increase in the temperature of the piston gas that was caused when the piston gas entered the first vessel 121.
In the same manner as described above with reference to
In a fourth step 104 of the method, the first gas is replenished. In the apparatus 110 of
The method of
In certain embodiments, the first vessel 121 of the apparatus 110 may be thermally insulated to further reduce the temperature in the receiving vessel after transferring gas. The insulation (not shown) may be provided within the first vessel 121 so that the first vessel 121 is thermally insulated from gas contained within the first vessel 121. Thus, heat flow between the first vessel 121 and any gas contained within the first vessel 121 may be reduced. Additionally or alternatively, the first vessel 121 may be insulated from its surrounding environment. Thus, heat flow between the first vessel and the surrounding environment may be reduced. In such embodiments, the method of
The method may also comprise storing the second volume of the first gas in a thermally insulated vessel prior to displacing at least some of the second volume of the process gas into the receiving vessel 113 using the piston gas. The thermal insulation then reduces heat flow into the second volume of the process gas so that the decrease in temperature during the second step 101 of the method is maintained.
Providing the insulation within the first vessel 121 so that the first vessel 121 is thermally insulated from gas contained within the first vessel 121 is particularly advantageous when the method of
In certain embodiments, the apparatus 110 may comprise a heat exchanger (not shown). The second vessel 122 may be thermally coupled to the heat exchanger. The heat exchanger may be arranged to remove heat from gas contained in the second vessel 122. The heat exchanger may be configured to cool gas contained in the second vessel 122 to ambient air temperature. Thus, as the first volume of the first gas resides in the second vessel 122 during the second step 101 of the method, heat flows through the heat exchanger cooling the first volume of the first gas towards ambient air temperature. This is advantageous because at least some of the first volume of the first gas may be received by the receiving vessel 113 as the method is repeated. The heat exchanger may comprise any heat exchanger capable of cooling to ambient air temperature may be used. For example, the heat exchanger may comprise an air source convective heat exchanger. The heat exchanger may comprise block of metal or a water cooled system both of which comprise means to cool the block or water to ambient air temperature.
The apparatus 210 comprises an auxiliary vessel 211, intermediate vessels and a receiving vessel 213. The intermediate vessels comprise a first vessel 241 and a second vessel 242. Each vessel 211, 241, 242, 213 is configured to receive and store gas.
The first vessel 241 comprises a first opening 251 and a second opening 252. The auxiliary vessel 211 is selectively fluidly connectable to the first opening 251 of the first vessel 241 such that a fluid path selectively connects the auxiliary vessel 211 and the first vessel 241. The first vessel 241 is selectively fluidly connectable to the auxiliary vessel 211 such that gas may flow from the auxiliary vessel 211 into the first vessel 241 without passing through the second vessel 242. As shown in
The second opening 252 of the first vessel 241 is selectively fluidly connectable to the second opening 254 of the second vessel 242 so that a fluid path 264 selectively connects the second opening 252 of the first vessel 242 to the second opening 254 to the second vessel 242.
The apparatus 210 comprises an intermediate valve 272 on the fluid path 264 connecting the first vessel 241 and the second vessel 242. The intermediate valve 272 controls the flow of gas between second opening 252 of the first vessel 241 and the second opening 254 of the second vessel 242. The intermediate valve 272 may be located anywhere along the fluid path 264 connecting the first vessel 241 and the second vessel 242.
The apparatus 210 comprises a heat exchanger 281. The heat exchanger 281 may comprise any heat exchanger capable of cooling gas to ambient temperature. The heat exchanger 281 is arranged on the fluid path 264 connecting the second opening 252 of the first vessel 241 and the second opening 254 of the second vessel 242. The apparatus 210 comprises a first restriction 282 and a second restriction 283, arranged one on either side of the heat exchanger 281. The first and second restrictions 282, 283 help facilitate a pressure drop between the first and second vessels 241, 242. The first and second restrictions 282, 283 are arranged so that gas flowing along a fluid path 264 from the second opening 252 of the first vessel 241 to the second opening 254 of the second vessel 242 does so via the first and second restrictions 282, 283 and the first heat exchanger 281.
The apparatus 210 may be configured so that each of the auxiliary vessel 211 and the receiving vessel 213 can be disconnected from the intermediate vessels. Thus, during use, the auxiliary vessel 211 and/or the receiving vessel 213 may be replaceable in the apparatus 210. The auxiliary vessel 211 may be a high-pressure storage vessel having a larger volume compared to one or both of the intermediate vessels 241, 242. The receiving vessel 213 may have a larger volume than one or both of the intermediate vessels 241, 242. The receiving vessel 213 may comprise a fuel tank within a vehicle or a machine. However, the method is not limited to such receiving vessels 213.
The method of
Before the start of the method of
The first step 203 of the method comprises providing a process gas. In the apparatus of
The second step 201 of the method comprises expanding the process gas (i.e. the gas in the first vessel 241) to produce a first volume of the process gas having a second temperature that is greater than the first temperature and a second volume of the process gas having a third temperature that is less than the first temperature. The process gas is expanded by opening the intermediate valve 272 to provide a fluid path 264 between the first vessel 241 and the second vessel 242. The process gas in the first vessel 241 expands into the second vessel 242 which is at a lower pressure than the first vessel 241. Therefore, at the end of the second step 201 of the method the first volume of the process gas has entered the second vessel 242 and the second volume of the process gas resides in the first vessel 241. In the same manner as described in the other embodiments, the second volume of process gas is cooled when it expands within the first vessel 241. The portion of the process gas which expands into the second vessel 242 flows through the heat exchanger 281 where it is cooled towards ambient temperature prior to entering the second vessel 242. Cooling the gas by the heat exchanger 281 reduces the second temperature. As will be described below, the portion of the process gas which expands into the second vessel 242 displaces gas from the second vessel 242 into the receiving vessel 213.
At the end of the second step 201 of the method, the temperature of the first vessel 241 has decreased. The process gas is expanded in the second step 201 so that the second volume of process gas is at substantially the same pressure as the gas contained in the second vessel 242 and the receiving vessel 213.
The third step 202 of the method comprises displacing at least some of the second volume of process gas from the first vessel 241 into the receiving vessel 213 using a piston gas. In the embodiment of
The third step of 202 ends when the receiving vessel 213, first vessel 241 and second vessel 242 have reached substantially the same pressure. The first vessel 241 has now returned to substantially the same pressure it was in at the start of the method. Thus, the method can be repeated to transfer more gas into the receiving vessel 213. Whilst the third step 202 of the method is performed in the first vessel 241, the second step 201 of the method is performed in the second vessel 242. Thus, when the first vessel 241 comes to the end of the third step of the method, the second vessel 242 contains a cooled volume of gas ready to be displaced into the receiving vessel 213 when the first vessel 241 next undergoes the second step 201 of the method.
In the method of
The method of
In the same manner as described above with reference to
The apparatus 310 comprises an auxiliary vessel 311, intermediate vessels and a receiving vessel 313. The intermediate vessels comprise a first vessel 341, a second vessel 342, a third vessel 343 and a fourth vessel 344. Each vessel 311, 341, 342, 343, 344, 313 is configured to receive and store gas.
The first vessel 341 comprises a first opening 351 and a second opening 352. The auxiliary vessel 311 is selectively fluidly connectable to the first opening 351 of the first vessel 341 such that a fluid path 361 selectively connects the auxiliary vessel 311 and the first vessel 341. The first vessel 341 is selectively fluidly connectable to the auxiliary tank 311 such that gas may flow from the auxiliary vessel 311 into the first vessel 341 without passing through the second vessel 342, the third vessel 343 or the fourth vessel 344. As shown in
The second opening 352 of the first vessel 342 is selectively fluidly connectable to the first opening of each of the second vessel 342, the third vessel 343 and the fourth vessel 344 so that a fluid path 363 selectively connects the second opening 352 of the first vessel 342 to the first opening to the second vessel 342, to the first opening to the third vessel 343 and to the first opening to the fourth vessel 344.
The second opening 352 of the first vessel 341 is also selectively fluidly connectable to the second opening of each of the second vessel 342, the third vessel 343 and the fourth vessel 344 so that a fluid path 364 selectively connects the second opening 352 of the first vessel 341 to the second opening to the second vessel 342, to the second opening to the third vessel 343 and to the second opening to the fourth vessel 344.
The second opening 352 of the first vessel 341 is fluidly connected to a second valve 372 to control the flow of gas between second opening 352 of the first vessel 341 and the first opening on another vessel and between the second opening 352 of the first vessel 341 and the second opening of another vessel. In alternative embodiments, the apparatus 310 may comprise separate valves may control the flow of gas between the second opening 352 of the first vessel 341 and the other vessels.
The second openings of the second vessel 342, the third vessel 343 and the fourth vessel 344 are connected to the first openings and second openings of the other vessels in the same manner as described for the first vessel 341.
The apparatus 310 comprises a first heat exchanger 381. The first heat exchanger 381 may comprise any heat exchanger capable of cooling gas to ambient temperature. The first heat exchanger 381 is arranged on the fluid path 363 connecting the second opening 352 of one of the first vessel 341, the second vessel 342, the third vessel 343 and the fourth vessel 344 with the first opening of another vessel. The apparatus 310 comprises two first restrictions 382, 383, arranged one on either side of the first heat exchanger 381. The first restrictions 382, 383 are arranged so that gas flowing along a fluid path from the second opening of one of the first vessel 341, the second vessel 342, the third vessel 343 and the fourth vessel 344 to the first opening of another the first vessel 341, the second vessel 342, the third vessel 343 and the fourth vessel 344 does so via the first restrictions 382, 383 and the first heat exchanger 381.
The apparatus 310 comprises a second heat exchanger 385. The second heat exchanger 385 may comprise any heat exchanger capable of cooling gas to ambient temperature. The second heat exchanger 385 is arranged on the fluid path connecting the second opening of one of the first vessel 341, the second vessel 342, the third vessel 343 and the fourth vessel 344 with the second opening of another of the first vessel 341, the second vessel 342, the third vessel 343 and the fourth vessel 344. The apparatus 310 comprises two second restrictions 386, 387, arranged one on either side of the second heat exchanger 385. The restrictions 386, 387 are arranged so that gas flowing along a fluid path from the second opening of one the first vessel 341, the second vessel 342, the third vessel 343 and the fourth vessel 344 to the second opening of another of the first vessel 341, the second vessel 342, the third vessel 343 and the fourth vessel 344 does so via the restrictions 386, 387 and the second heat exchanger 385.
The apparatus 310 may be configured so that each of the auxiliary vessel 311 and the receiving vessel 313 can be disconnected from one, more than one, or all of the intermediate vessels 341, 342, 343, 344. Thus, during use, the auxiliary vessel 311 and/or the receiving vessel 313 may be replaceable in the apparatus 310. The vessels shown in
The method of
Before the start of the method of
The first step 303 of the method comprises displacing the first gas to provide a process gas. In the apparatus 310 of
At the end of the first step 303 of the method, the first gas in the first vessel 341 has been replaced by the auxiliary gas. The first valve 371 is used to close the fluid path 361 between the auxiliary vessel 311 and the first vessel 341 and the second valve 372 is used to close the fluid path 363 between the first vessel 341 and the fourth vessel 344. The auxiliary gas which fills the first vessel 341 at the end of the first step 303 has a first temperature and fulfils the same role as the process gas of the method of
The second step 301 of the method comprises expanding the process gas to produce a first volume of the process gas having a second temperature that is greater than the first temperature and a second volume of the process gas having a third temperature that is less than the first temperature. The process gas is expanded by opening the second valve 372 on the second opening 352 of the first vessel 341 to provide a fluid path 364 between the first vessel 341 and the second vessel 342. The process gas in the first vessel 341 expands into the second vessel 342 which is at a lower pressure than the first vessel 341. Therefore, at the end of the second step 301 of the method the first volume of the process gas resides in the second vessel 342 and the second volume of the process gas resides in the first vessel 341. In the same manner as described in the other embodiments, the second volume of process gas is cooled when it expands within the first vessel 341. The portion of the process gas which expands into the second vessel 342 flows through the second heat exchanger 385 where it is cooled towards ambient temperature prior to entering the second vessel 342. As this portion of the process gas expands into the second vessel 342, it is used to perform the third step 302 of the method (described below) in the second vessel 342.
At the end of the second step 301 of the method, the temperature of the first vessel 341 has decreased. The process gas may be expanded in the second step 301 so that the second volume of process gas is at substantially the same pressure as the gas contained in the receiving vessel 313. The second valve 372 is used to close the fluid path 364 between the first vessel 341 and the second vessel 342 at the end of the second step 301.
The third step 302 of the method comprises displacing at least some of the second volume of process gas into the receiving vessel 313 using a piston gas. In the apparatus of
The third step of the method ends when the fourth vessel 343, first vessel 341 and receiving vessel 313 have reached substantially the same pressure. At the end of the third step of the method, the first valve 371 is used to close the fluid path 362 between the first vessel 341 and the receiving vessel 313 and the second valve 372 is used to close the fluid path 363 between the first vessel 341 and the fourth vessel 343.
In the same manner as described above with reference to
The fourth step 304 of the method comprises replenishing the first gas. In the apparatus 310 of
At the end of the fourth step 304 of the method, the first vessel 341 has returned to the initial condition it had prior to the first step 303 of the method. The gas in the first vessel 341 has been re-pressured in the fourth step 304 of the method. Therefore, the method can be repeated to transfer more gas into the receiving vessel 313. Whilst the method is described as starting at the first step 303 in the first vessel 341, the method may be performed in the apparatus 310 starting at any step depending on the initial pressures in the vessels.
During the implementation of the method, one of the intermediate vessels is subject to one of the four method steps at any one time.
The method of
The apparatus 310 shown in
In the process diagram of
Each of the intermediate vessels 341, 342, 343, 344 repeatedly cycles through the method step shown in
The apparatus 510 comprises an auxiliary vessel 511, intermediate vessels and a receiving vessel 513 The intermediate vessels comprise a first pair of vessels 541, a second pair of vessels 542, a third pair of vessels 543 and a fourth pair of vessels 544. Each pair of vessels comprises a first vessel and a second vessel. Each vessel 511, 541a, 542a, 543a, 544a, 541b, 542b, 543b, 544b, 513 in the apparatus 510 is configured to receive and store gas.
The first vessel 541a of the first pair of vessels 541 comprises a first opening 551 and a second opening 552. The auxiliary vessel 511 is selectively fluidly connectable to the first opening 551 of the first vessel 541a such that a fluid path selectively connects the auxiliary vessel 511 and the first vessel 541a of the first pair of vessels 541. The first vessel 541 is selectively fluidly connectable to the auxiliary tank 511 such that gas may flow from the auxiliary vessel 511 into the first vessel 541 without passing through any other vessel. As shown in
The second opening 552 of the first vessel 541a of the first pair of vessels 541 is selectively fluidly connectable to a first opening 553 of the second vessel 541b of the first pair of vessels 541 such that gas may flow from the first vessel 541a into the second vessel 541b. The apparatus 510 comprises a valve configured to control the flow of gas out of the second opening 552 of the first vessel 541a and a valve configured to control the flow of gas into the first opening 553 of the second vessel 541b of the first pair of vessels 541. The second opening 552 of the first vessel 541a of the first pair of vessels 541 is also selectively fluidly connectable to the second opening of the second vessel of each of the second pair of vessels 542, the third pair of vessels 543 and the fourth pair of vessels 544. As such, gas may flow from the first vessel 541a into the second vessel of each of the second pair of vessels 542, the third pair of vessels 543 and the fourth pair of vessels 544 without flowing through the second vessel 541b of the first pair of vessels 541.
A second opening 554 of the second vessel 541b of the first pair of vessels 541 is selectively fluidly connectable to the first opening of the first vessel of each of the second pair of vessels 542, the third pair of vessels 543 and the fourth pair of vessels 544. As such, gas may flow from the second vessel 541b of the first pair of vessels 541 into the first vessel of each of the second pair of vessels 542, the third pair of vessels 543 and the fourth pair of vessels 544. The second opening 554 of the second vessel 541b of the first pair of vessels 541 is also selectively fluidly connectable to the second opening of the second vessel of each of the second pair of vessels 542, the third pair of vessels 543 and the fourth pair of vessels 544. As such, gas may flow from the second vessel 541b of the first pair of vessels 541 into the second vessel of each of the second pair of vessels 542, the third pair of vessels 543 and the fourth pair of vessels 544.
The openings of the first and second vessels in the second pair of vessels 542, the third pair of vessels 543 and the fourth pair of vessels 544 are connected to the first openings and second openings of the other vessels in the same manner as described for the first vessel 541. The apparatus 510 comprises a plurality of valves. Each vessel has a valve positioned adjacent to its first opening and its second opening to control the flow of gas into and out of each vessel.
The apparatus 510 comprises a plurality of first heat exchangers 581, 585, 591, 595. The apparatus 510 is configured so that gas flowing between any of the intermediate vessels may pass through one of the plurality of first heat exchangers 581, 585, 591, 595. For example, gas flowing from the first vessel 541a in the first pair of vessels 541 to the second vessel 541b in the first pair of vessels 541 may pass through one of the plurality of first heat exchangers 581, 585, 591, 595. Additionally, gas flowing from the second vessel 541b of the first pair of vessels 541 to the second vessel 542b in the second pair of vessels 542 may pass through one of the plurality of first heat exchangers 581, 585, 591, 595. Each of the plurality of first heat exchangers 581, 585, 591, 595 may comprise radiator. Each radiator may be configured to cool gas flowing through it to the ambient temperature. In the same manner as described for the apparatus 310 of
As shown in
The apparatus 510 may be configured so that each of the auxiliary vessel 511 and the receiving vessel 513 can be disconnected from one, more than one, or all of the intermediate vessels. Thus, during use, the auxiliary vessel 511 and/or the receiving vessel 513 may be replaceable in the apparatus 510. The vessels shown in
The apparatus 510 of
Before the start of the method, the auxiliary vessel 511 contains an auxiliary gas and the first pair of vessels 541 each contains a gas which has substantially the same pressure as the auxiliary gas in the auxiliary vessel 511. The second pair of vessels 542 contains a gas which is substantially the same pressure as the auxiliary gas in the auxiliary vessel 511. The third pair of vessels 543, the fourth pair of vessels 544 and the receiving vessel 513 each contain gas at a lower pressure than the auxiliary vessel 511 and first pair of vessels 541. The gas in all the vessels of the apparatus 510 is the same type of gas. The auxiliary gas may be at ambient temperature. The first gas may be at or above ambient temperature.
The first step 303 of the method comprises displacing the gas from the first pair of vessels 514. In the apparatus 510 of
At the end of the first step 303 of the method, the gas in the first pair of vessels 541 has been replaced and is at substantially the same pressure at gas in the auxiliary vessel 511. The gas which fills the first vessel 541a of the first pair of vessels 541 at the end of the first step 303 has a first temperature and fulfils the same role as the process gas of the method of
The second step 301 of the method comprises expanding the process gas in the first vessel 541a of vessel of the first pair of vessels 541 to produce a first volume of the process gas having a second temperature that is greater than the first temperature and a second volume of the process gas each having a third temperature that is less than the first temperature. The gas within the second vessel 541b of the first pair of vessels 541 is also expanded in a similar manner.
In this step the gas in each of the first vessel 541a and second vessel 541b of the first pair of vessels 541 is expanded into the second vessel 542b of the second pair of vessels 542. Thus, the first vessel 541a of the first pair of vessel 541 is fluidly connected to the second vessel 542b of the second pair of vessels 542 and the second vessel 541b of the first pair of vessel 541 is fluidly connected to the second vessel 542b of the second pair of vessels 542. The process gas in the first vessel 541a and the gas in the second vessel 542b expands into the second vessel 542b of the second pair of vessels 542 which is at a lower pressure than the first pair of vessels 341. In this step the first and second vessels 541a, 541b of the first pair of vessels 541 are not fluidly connected. Thus, gas does not pass between the first and second vessels 541a, 541b of the first pair of vessels 541. Rather, gas flows independently from each of the first and second vessels of the first pair of vessels 541 into the second vessel 542b of the second pair of vessels 542.
At the end of the second step 301 of the method, the second volume of the process gas resides in the first vessel 541a of the first pair of vessels 541. The second vessel 541b of the of the first pair of vessels 541 contains a similar volume of gas. In the same manner as described in the other embodiments, the gas in the first vessel 541a and second vessel 542b of the first pair of vessels 541 is cooled when it expands within the respective vessel. Thus, the gas residing in the first and second vessel 541a, 541b is below ambient temperature at the end of the second step 301. The gas which expands into the second pair of vessels 542 during the second step 310 flows through one of the plurality of first heat exchangers 585 where it is cooled towards ambient temperature prior to entering the second vessel 542b of the second pair of vessels 542. The gas which expands into the second vessel 542b of the second pair of vessels 542, it is used to perform the third step 302 of the method (described below) in the second pair of vessels 542.
At the end of the second step 301 of the method, the temperature of the first pair of vessels 541 has decreased (i.e. each vessel contains a cooled volume of gas) and the pressure of gas in each of the first pair of vessels 541 is at substantially the same pressure as the gas contained in the receiving vessel 513.
The third step 302 of the method comprises displacing at least some of the second volume of process gas into the receiving vessel 513 using a piston gas. That is, the second volume of process gas within the first vessel 541a of the first pair of vessels 541 is displaced into the receiving vessel 513. In the apparatus of
The piston gas is cooled prior to entering the second vessel 541b of the first pair of vessels 541 one of the plurality of first heat exchangers 585, 595 thereby reducing the final temperature in the second vessel 541b of the first pair of vessels 541 after the piston gas has displaced the gas from this vessel.
As the cooled volume of gas from the second vessel 541b is displaced into the first vessel 541a of the first pair of vessels 541 by the piston gas, it passes through the second heat exchanger 599. The second heat exchanger extracts coolth from the cooled volume of gas which may be used to cool gas elsewhere within the apparatus 510 or for an alternative purpose.
The third step 302 of the method ends when the second volume of process gas from the first vessel 541a has been displaced into the receiving vessel 513. At the end of the third step 302 of the method the first vessel 541a is filled with the gas which resided within the second vessel 541b of the first pair of vessels 541 at the end of the second step 301 of the method. Additionally, at the end of the third step of the method the fourth pair of vessels 543, first pair of vessels 541 and receiving vessel 513 are at substantially the same pressure.
In the same manner as described above with reference to
The fourth step 304 of the method comprises replenishing the gas in the first pair of vessels 541. In the apparatus 510 of
At the end of the fourth step 304 of the method, the first pair of vessels 541 have returned to their initial condition it had prior to the first step 303 of the method. The gas in the first pair of vessels 541 has been re-pressured in the fourth step 304 of the method. Therefore, the method can be repeated to transfer more gas into the receiving vessel 313. Whilst the method is described as starting at the first step 303 in the first vessel 341, the method may be performed in the apparatus 510 starting at any step depending on the initial pressures in the vessels. During the implementation of the method, one of the pairs of intermediate vessels is subject to one of the four method steps at any one time. Transferring gas using the apparatus 510 of
In each of the above described embodiments, the piston gas is of the same type as the process gas. The process gas, the piston gas and any other gas within the vessels of any of the above-described embodiments may each be a compressed gas. The compressed gas may comprise oxygen, nitrogen, argon, helium, hydrogen, compressed natural gas, methane and mixtures thereof. Such mixtures may include, for example, a mixture of oxygen and nitrogen. In certain embodiments, the piston gas and the process gas may each be a fuel gas. A fuel gas may comprise compressed natural gas, hydrogen or any other gas suitable for use as a fuel. Any gas in the receiving vessel at the start of the method is the same type of gas as the process gas.
Various modifications to the above-described embodiments will be apparent to the skilled person.
In the above described embodiments of the method of transferring gas, the efficiency of cooling the process gas during the step of expanding the process gas may be limited by the relative initial pressures of gas in the auxiliary vessel and the receiving vessel. That is, the efficiency may depend on the pressure ratio of gas in the auxiliary vessel to gas in the receiving vessel. If the initial pressure of gas in the auxiliary vessel is too high relative to the initial pressure of gas in the receiving vessel, when the process gas expands to produce the cooler second volume of the process gas, the resulting second volume may overflow from the intermediate vessel in which it expands. In certain embodiments, the gas may overflow into a heat exchanger where it may be warmed to ambient temperature. Thus, the reducing the efficiency of cooling the gas as it is transferred from the auxiliary vessel to the receiving vessel.
The pressure ratio limit is the ratio of the pressure of gas in the auxiliary vessel to the pressure of gas in the receiving vessel above which the second volume of process gas overflows the intermediate vessel. The pressure ratio limit depends on the number of intermediate vessels used to transfer the gas to a receiving vessel and on the type of gas which is transferred. When transferring hydrogen from an auxiliary vessel with an initial pressure of 450 bar and temperature of 15° C., the pressure limit ratio for the apparatus 110 shown in
When transferring gas from an auxiliary vessel to a receiving vessel where the pressure ratio is above the pressure ratio limit, the above-described methods may be modified to improve efficiency of cooling the gas during transfer. In certain embodiments, the method shown in
Before the start of the method, the auxiliary vessel 311 contains an auxiliary gas and the first vessel 341 contains a first gas which has substantially the same pressure as the auxiliary gas in the auxiliary vessel 311. The second vessel 342 contains a gas which has substantially the same pressure as the auxiliary gas in the auxiliary vessel 311. The third vessel 343, the fourth vessel 344 and the receiving vessel 313 each contain gas at a lower pressure than the auxiliary vessel 311 and first vessel 341. The gas in all the vessels of the apparatus 310 is the same type of gas. The auxiliary gas may be at ambient temperature. The first gas may be at or above ambient temperature.
The first step of the method 1303 of displacing a first gas to provide a process gas comprises a first period 1303a and a second period 1303b. In the first period 1303a, there is no change to the gas within the first vessel 341. During the second period 1303b, the first gas within the first vessel 342 is displaced to provide a process gas. The first gas is displaced from the first vessel 341 with the auxiliary gas. The first gas that is expelled from the first vessel 341 may enter the fourth vessel 344 where it is used to perform the second period 1304b of fourth step 1304 (described below) in the fourth vessel 344. At the end of the first step 1303 of the method, the first gas in the first vessel 341 has been replaced by the auxiliary gas.
The second step 1301 of the method comprises expanding the process gas to produce a first volume of the process gas having a second temperature that is greater than the first temperature and a second volume of the process gas having a third temperature that is less than the first temperature. The process gas in the first vessel 341 is expanded such that at the end of the second step 1301 the second volume of the process gas resides in the first vessel 341 and the first volume of the process gas resides in two different intermediate vessels. The second step 1301 is divided into a first period 1301a and a second period 1301b, in the first period 1301a and the second period 1303b the destination of the first volume of the process gas which leaves the first vessel 341 differs. In the first period 1301a, a first portion of the first volume of the process gas leaving the first vessel 341 is used to replenish the first gas in the third vessel 343 i.e. to perform the first period 1304a of fourth step 1304 of the method (described below) in the third vessel 343. The first period 1301a may end when the pressure in the first vessel 341 and the third vessel 343 are substantially the same. Alternatively, the first period 1301a may end which the pressure in the first vessel 341 is still greater than the pressure in the third vessel 343. During the second period 1301b of the second step 1301, a second portion of the first volume of the process gas leaving the first vessel 342 is used as the piston gas to displace gas from the second vessel into the receiving vessel 313. That is, to perform the second period 1303b of the third step 1303 (described below) in the second vessel 342. Expanding the process gas in this manner reduces the overflow of the second volume of process gas from the first vessel 341 when it expands thereby improving the efficiency of method for cooling the process gas. Providing two periods in which the process gas leaving the first vessel 341 is delivered to different destinations results in each of the method steps having two periods.
The third step of the method 1302 comprising displacing at least some of the second volume of the process gas using a piston gas is divided into a first period 1302a and a second period 1302b. In the first period 1302a, there is no change to the gas within the first vessel 341. During the second period 1302b, the second volume of process gas is displaced into the receiving vessel 313 using the piston gas. The gas in the fourth vessel 343 provides the piston gas for the first vessel 341. The third step of the method 1303 ends when the fourth vessel 343, first vessel 341 and receiving vessel 313 have reached substantially the same pressure. In the same manner as above described embodiments, the piston gas may cause at least some of the second volume of the process gas to substantially flow according to a plug flow regime into the receiving vessel 313.
The fourth step 1304 of the method comprising replenishing the first gas by increasing the pressure in the first vessel 341 to substantially the same pressure as the auxiliary vessel 311. The fourth step is also divided into a first period 1304a and a second period 1304b. In the first period 1304a of the fourth step, the first gas is replenished using gas exiting the third vessel 343 which is undergoing the first period 1301a of the second step 1301 of expanding the process gas. In the second period 1304b of the fourth step 1304, the first gas is replenished using gas from the second vessel 342 which is undergoing the second period 1303a of the first step 1303. The fourth step 1304 of the method ends when the first vessel 341, second vessel 342 and auxiliary vessel 311 have reached substantially the same pressure.
Dividing each of the method steps into two separate periods improves the efficiency of method for cooling the process gas for the apparatus 310 when the pressures of the auxiliary and receiving vessels are above pressure ratio limit of 3. The modified method of
The above-described method of transferring gas using the apparatus 510 of
In certain embodiments, the above-described method of transferring gas using the apparatus 510 may be modified by splitting each of the method steps into a first period and a second period as shown in
In the first period 1301a of the second step 1301 of the method, a first portion of the gas leaving each of the first vessel 514a and the second vessel 541b of the first pair of vessels 541 is used to replenish the third pair of vessels 343. That is, the gas exiting each of the first vessel 514a and the second vessel 541b of the first pair of vessels 541 enters the second vessel 543b of the third pair of vessels 343 to replenish the third pair of vessels 543 i.e. to perform the first period 1304a of fourth step 1304 of the method (described below) in the third pair of vessels 543. The first period 1301a may end when the pressure in the first pair of vessels 541 and the third pair of vessels 543 are substantially the same. Alternatively, the first period 1301a may end which the pressure in the first pair of vessels 541 is still greater than the pressure in the third pair of vessels 543. During the second period 1301b of the second step 1301, a second portion of the gas leaving each of the first vessel 541a and the second vessel 541b of the first pair of vessels 541 is used as the piston gas to displace gas from the second pair of vessels 542 into the receiving vessel 513. That is, gas exiting each of the first vessel 541a and the second vessel 541b of the first pair of vessels 541 enters the second vessel 542b of the second pair of vessels 542 to perform the second period 1303b of the third step 1303 (described below) in the second vessel 342. Expanding the gas in this manner reduces the overflow of the gas from the first pair of vessels 541 when it expands thereby improving the efficiency of method for cooling the process gas. During the second step 1301 of the method, there is no flow of gas between the first vessel 541a and the second vessel 541b of the first pair of vessels 541.
In the first period 1302a of the third step of the method 1302, there is no change to the gas within the first pair of vessels 541. During the second period 1302b of the third step of the method 1302, the gas in each of the first and second vessels 541a, 541b of the first pair of vessels are displaced from the first pair of vessels 541 using the piston gas. The gas in the fourth pair of vessels 544 provides the piston gas for the first pair of vessels 541. That is, gas exiting the second vessel 544b of the fourth pair of vessels 544 enters the second vessel 541b of the first pair of vessels to displace the second volumes of process gas. The third step of the method 1303 ends when the fourth pair of vessels 544, first pair of vessels 541 and receiving vessel 513 have reached substantially the same pressure.
In the first period 1304a of the fourth step 1304 of the method, the first gas in the first pair of vessels is replenished using gas exiting the third pair of vessels 543 which is undergoing the first period 1301a of the second step 1301. That is, gas exiting the second vessel 543b of the third pair of vessels 543 enters the first vessel 541a of the first pair of vessels 541 to replenish the first pair of vessels 541. In the second period 1304b of the fourth step 1304, the gas in the first pair of vessels is replenished using gas from the second pair of vessels 542 which is undergoing the second period 1303a of the first step 1303. Thus, gas exiting the second vessel 542b of the second pair of vessels 542 enters the first vessel 541a of the first pair of vessels 541 to replenish the first pair of vessels 541. The fourth step 1304 of the method ends when the first pair of vessels 541, second pair of vessels 542 and auxiliary vessel 511 have reached substantially the same pressure as one another.
Dividing each of the method steps into two separate periods as shown in
In each of the above described embodiments, the orientation of the intermediate vessels is not limited to the arrangement shown in the Figures. In the arrangement of intermediate vessels shown in
In certain embodiments, the relative sizes of the vessels may differ from those in the above described embodiments. In alternative embodiments to the apparatus 110 of
The apparatus 10 of
The method shown in
In certain embodiments, the first 1 and second 2 steps of the method shown in
In certain embodiments, the second 101 and third 102 steps of the method shown in
In certain embodiments, the fluid paths between the first vessel 341, second vessel 342, third vessel 343 and fourth vessel 344 may be different to those shown in the apparatus 310 of
In certain embodiments, the apparatus 310 of
In certain embodiments, the apparatus 210 of
In certain embodiments, a chain may be formed from multiple apparatuses 310 of
Throughout the specification, “substantially the same” when referring to two or more vessels being at substantially the same pressure may be understood to mean that there is a 10% or less, a 5% or less, or a 2% or less difference in the pressure of the vessels. For example, two vessels may be considered to have substantially the same pressure when the two pressures of the vessels measured in Barg are between 0 and 10%, 0 and 5%, or 0 and 2% of each other. This pressure range may help to optimize the speed at which gas is transferred to the receiving vessels versus efficiency of controlling the temperature in the receiving vessel.
Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.
Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2105161.0 | Apr 2021 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2022/050917 | 4/12/2022 | WO |
