Abstract
A transfer system is provided for transferring temperature sensitive fluids from a supply tank to a receiver tank. The supply and the receiver tank (101,102) are fluidly connected by a piping arrangement comprising at least two thermally insulated transfer lines (103a, 103b) and first and second piping assemblies (104a-d) associated with the receiver and the supply tank, respectively. One end of each transfer line is connected with one of the supply and receiver tank and the other end of each transfer line is provided with a coupling for coupling the other end with the other one of the supply and receiver tank. The transfer system (100) is selectively operable in a transfer mode and an idle mode by appropriately coupling and decoupling the first and second transfer lines. In either mode the piping arrangement remains at or close to an operating temperature of the transfer system in the transfer mode.
Claims
1. A transfer system for transferring temperature sensitive fluids from a supply tank to a receiver tank, wherein the supply tank and the receiver tank are fluidly connected by a piping arrangement, said piping arrangement comprising: at least two thermally insulated transfer lines; and first and second piping assemblies associated with the receiver and the supply tank, respectively, wherein one end of each transfer line is connected with one of the supply and receiver tank and the other end of each transfer line is provided with a coupling for coupling the other end with the other one of the supply and receiver tank, wherein the transfer system is selectively operable in a transfer mode and an idle mode by appropriately coupling and decoupling the first and second transfer lines, wherein, in the transfer mode, the first and the second transfer lines fluidly connect the supply tank with the receiver tank, such that fluid flows through the first and second transfer lines and the first and second pipe assemblies, and in that, in the idle mode, the first and second transfer lines form a closed loop enabling a continuous flow of fluid through the first and second transfer lines, and in that the first and the second pipe assemblies are part of the closed loop enabling a continuous flow of fluid through the first and the second pipe assemblies.
2. The transfer system according to claim 1, wherein the first pipe assembly conducts a liquid phase of the fluid, and the second pipe assembly conducts a gaseous phase of the fluid.
3. The transfer system according to claim 1, wherein the first and the second pipe assemblies form at least one other closed loop that is separate from the closed loop of the transfer lines.
4. The transfer system according to claim 1, wherein a connection pipe connects two pipe assemblies.
5. The transfer system according to claim 4, wherein a shut-off valve is arranged in the connection pipe that can selectively assume an open and a closed state.
6. The transfer system according to claim 1, wherein the first and the second transfer lines are divided into two sections, wherein each section is connected with the receiver and the supply tank, respectively, and wherein the sections of the first and second transfer lines are coupled with releasable couplings to each other.
7. The transfer system according to claim 6, wherein the sections of the first and second transfer line form closed loops in the idle mode of the transfer system, wherein each of the closed loops includes one pipe assembly.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Exemplary embodiments of the present disclosure are illustrated in the drawings and are explained in more detail in the following description. In the figures, the same or similar elements are referenced with the same or similar reference signs. It shows:
[0030] FIGS. 1A, B a first embodiment of a transfer system according to the present disclosure in a transfer und idle mode, respectively,
[0031] FIGS. 2A, B a second embodiment of a transfer system according to the present disclosure in a transfer und idle mode, respectively,
[0032] FIGS. 3A, B a third embodiment of a transfer system according to the present disclosure in a transfer und idle mode, respectively, and
[0033] FIGS. 4A, B a fourth embodiment of a transfer system according to the present disclosure in a transfer und idle mode, respectively,
DETAILED DESCRIPTION
[0034] The detailed description of embodiments makes reference to liquefied hydrogen as an example for temperature sensitive fluid. However, the invention is not limited to any specific temperature sensitive fluid. Liquefied hydrogen (LH2) is only chosen as an example of high importance for practical applications.
[0035] FIG. 1A shows a schematic illustration of a first embodiment of a transfer system 100 in a transfer operation mode. The transfer system 100 includes a receiver and a supply tank 101, 102 which are interconnected by a first and a second transfer line 103a, 103b. The receiver tank 101 is equipped with fixedly attached pipe assemblies 104a, 104b, each of which forms a closed loop that is provided with a detachable coupling 106a, 106b. The couplings are for instance self-closing dry QC/DC (quick connect/disconnect) couplings, which are known in the art. Likewise, the supply tank 102 is equipped with fixedly attached pipe assemblies 104c, 104d, which are provided with detachable couplings 106c, 106d, respectively. The pipe assemblies 104c, 104d also form closed loops similar to the pipe assemblies 104a, 104b. One end of the transfer line 103a is fixedly attached to the pipe assembly 104c. The other end of the first transfer line 103a is fitted with a coupling 107a, which is coupled with the coupling 106a of the pipe assembly 104a. One end of the second transfer line 103b is fixedly attached to the pipe assembly 104d of the supply tank 102. The other end of the second transfer line 103b is fitted with a coupling 107b, which is coupled with the coupling 106b of the pipe assembly 104b of the receiver tank 101. In the transfer mode shown in FIG. 1A liquefied fluid, for instance LH2 is transferred from the supply tank 102 to the receiver tank 101 through the first transfer line 103a. Gaseous fluid is flowing back through the second transfer line 103b from the receiver tank 101 to the supply tank 102 where it is reliquefied by a cooling system (not shown). In this way no gaseous fluid escapes into the environment. In the case of LH2 the temperature of the liquefied with his 20 K and the temperature of the gaseous fluid, namely gaseous hydrogen (GH2) is 30 K.
[0036] When the filling of the receiver tank 101 is completed, for instance when it is filled up to its maximum capacity, the coupling 107a is separated from coupling 106a and connected with coupling 106c of the supply tank 102. Similarly, the coupling 107b is separated from coupling 106b and connected with coupling 106d of the supply tank 102. This configuration of the transfer system 100 is shown in FIG. 1B and corresponds to an idle mode of the transfer system 100.
[0037] In the idle mode of the transfer system 100 shown in FIG. 1B liquefied fluid flows through transfer line 103a and cold gaseous fluid flows through the transfer line 103b. In this way, the first and second transfer lines 103a,b are kept at operating temperature. At the same time the pipe assemblies 104c and 104d are kept at operating temperature as well because liquefied fluid circulates through the pipe assembly 104a and gaseous fluid flows through the pipe assembly 104b coupled with the receiver tank 101. Due to the continuous flow of cold fluid through the pipe assemblies 104a,b also the couplings 106a,b are maintained at low temperatures. As a result, in the idle mode of the transfer system there are essentially no parts of the transfer system 100 that warm up and need to be cooled down and purged before the transfer system 100 returns to the transfer mode. In the application case of the transfer of LH2 the temperature of liquefied fluid is 20 K and the temperature of gaseous fluid is 30 K.
[0038] The transfer lines 103a,b and the pipe assemblies 104a-d as a whole are referred to as piping arrangement.
[0039] In FIGS. 2A and 2B another embodiment of a transfer system 200 according to the present disclosure is shown. The main difference between the transfer system 200 and the transfer system 100 is that the pipe assemblies 104a-d in the transfer system 200 are simplified to straight pipes without forming individual loops. In spite of this simplification, the term pipe assembly will be used also in connection with the transfer system 200. One end of the first transfer line 103a is fixedly connected with the pipe assembly 104c and the other end of the first transfer line 103a is provided with a coupling 107a that is coupled with the coupling 106a arranged at the pipe assembly 104a connected with the receiver tank 101. One end of the second transfer line 103b is fixedly connected with the pipe assembly 104d and the other end of the second transfer line 103b is provided with a coupling 107b that is coupled with the coupling 106b arranged at the pipe assembly 104b connected with the receiver tank 101. A connection pipe 201 connects the pipe assemblies 104a and 104b. A shut-off valve 202 allows for selectively activating or deactivating the connection pipe 201, i.e. selectively allowing or blocking the flow of fluid between the pipe assemblies 104a and 104b when the shut-off valve 202 is in its open or closed state, respectively.
[0040] FIG. 2A shows the transfer system 200 in the transfer mode, i.e. when liquefied fluid (e.g. LH2) is transferred through the transfer line 103a from the supply tank 102 two the receiver tank 101. In the transfer mode the shut-off valve 202 is closed and prevents flow of fluid between the pipe assemblies 104a and 104b. Gaseous fluid passes from the receiving tank 101 through the transfer line 103b back to the supply tank 102 where it is reliquefied. It is noted that the pipe sections of connection pipe 201 between the pipe assemblies 104a and 104b remain at low temperatures due to turbulent flow of fluid from the transfer lines 103a and 103b.
[0041] FIG. 2B shows the transfer system 200 in the idle mode, i.e. when no liquefied fluid is transferred from the supply tank 102 two the receiver tank 101. In the idle mode coupling 107a of the first transfer line 103a is coupled to coupling 107b of the second transfer line 103b. Liquefied fluid flows through the first and the second transfer line 103a, 103b and keeps them at low temperatures. On the side of the receiver tank 101 the shut-off valve 202 is open and liquefied fluid is pumped through the pipe assemblies 104a and 104b, which are connected by the connection pipe 201. In this way also the pipe assemblies 104a, 104b and the couplings 106a, 106b are kept at low temperatures.
[0042] Alternatively, cold gaseous fluid can be used to keep the piping arrangement at or at least near the operating temperature of the transfer system in its transfer mode.
[0043] In order to return to the transfer mode of the transfer system 200 it is sufficient to close the shut-off valve 202, to decouple the coupling 107a from 107b and couple the coupling 107a and 107b with the coupling 106a and 106b, respectively. Cooling down and/or purging of the transfer lines 103a, 103b and the pipe assemblies 104a-d is not necessary.
[0044] FIGS. 3A and 3B illustrates another embodiment of a transfer system 300 according to the present disclosure. The transfer system 300 is very similar to the transfer system 100 and one difference is that the first transfer line 103a is replaced by two flexible transfer lines 301a and 302a. One end of transfer line 301a is fixedly connected with pipe assembly 104c and the other end of transfer line 301a is provided with the coupling 107a. One end of transfer line 302a is fixedly connected with pipe assembly 104a and the other end of transfer line 302a is provided with the coupling 106a. Likewise, one end of transfer line 301b is fixedly connected with pipe assembly 104d and the other end of transfer line 301b is provided with the coupling 107b. One end of transfer line 302b is fixedly connected with pipe assembly 104b and the other end of transfer line 302b is provided with the coupling 106b. In addition to that, every pipe assembly 104a-d is provided with a coupling 303a-d.
[0045] In the transfer mode shown in FIG. 3A the couplings 107a and 106a of transfer lines 301a and 302a are coupled. Similarly, the couplings 107b and 106b of transfer lines 301b and 302b are coupled. In the transfer mode liquefied fluid flows from the supply tank 102 through the pipe assembly 104c and through the transfer lines 301a and 302a to the pipe assembly 104a to the receiver tank 101. Gaseous fluid flows in the opposite direction through pipe assembly 104b through the transfer lines 302b and 302a to the pipe assembly 104 into the supply tank 102.
[0046] FIG. 3B shows the idle mode of the transfer system 300. To transition the transfer system from the transfer mode shown in FIG. 3A to the idle mode, the couplings 106a, 107a and 106b, 107b are decoupled from one another and coupled to the couplings 303a-d such that close to loops are formed by the transfer lines 301a,b 302a,b including the pipe assemblies 104a-d. As a result, liquefied fluid flows through the transfer lines 301a and 302a and the pipe assemblies 104a and 104c. Similarly, gaseous fluid flows through the transfer lines 301b and 302b and the pipe assemblies 104b and 104d. In this way, all transfer lines and pipe assemblies are kept at low temperatures enabling transitioning from the idle mode into the transfer mode without requiring cooling down or purging of the transfer lines and pipe assemblies.
[0047] FIGS. 4A and 4B show yet another transfer system 400 according to the present disclosure. The transfer system 400 is very similar to the transfer system 200. The pipe assemblies 104a-d are simplified again to straight pipes.
[0048] In the transfer mode shown in FIG. 4A, one end of the first transfer line 103a is fixedly connected with the pipe assembly 104c. the other end of the first transfer line 103a is equipped with a first coupling 107a connected with a coupling 106a arranged at the pipe assembly 104a. One end of the second transfer line 103b is fixedly connected with the pipe assembly 104b. The other end of the transfer line 103b is equipped with a coupling 107b is coupled to a coupling 106d arranged at the pipe assembly 104d. In this transfer mode liquefied fluid flows from the supply tank 102 through the pipe assembly 104c, the first transfer line 103a, the pipe assembly 104a to the receiver tank 101. Gaseous fluid returns through the pipe assembly 104b, the second transfer line 103b and the pipe assembly 104d into the supply tank.
[0049] In the idle mode when no fluid is transferred from the supply tank 102 to the receiver tank 101, the coupling 107a of the first transfer line 103a is coupled with the coupling 106d of the pipe assembly 104d. Likewise the second transfer line 103b is coupled with a coupling 107b to the coupling 106a of the pipe assembly 104a. In the idle mode liquefied fluid flows through the first and the second transfer line 103a,b and keeps them at low temperatures. Alternatively, cold gaseous fluid keeps the piping arrangement at or at least near the operating temperature of the transfer system in the transfer mode.
[0050] In order to return from the idle mode into the transfer mode only the couplings 107a and 107b of the first and second transfer lines 103a,b need to be decoupled and re-coupled as shown in FIG. 4A. The transition from the idle mode to the transfer mode is possible without requiring cooling down or purging of the transfer lines.
[0051] The embodiment of the transfer system according to the present disclosure has been described with liquefied hydrogen (LH2) as an example for a temperature sensitive fluid, the present disclosure is not limited to a specific temperature sensitive fluid.
[0052] In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a does not exclude a plurality.
[0053] A single unit or device may perform the functions of multiple elements recited in the claims. The fact that individual functions and elements are recited in different dependent claims does not mean that a combination of those functions and elements could not advantageously be used.
LIST OF REFERENCE SIGNS
[0054] 100 Transfer system [0055] 10 Receiver tank [0056] 102 Supply tank [0057] 103a,b Transfer line [0058] 104a-d Pipe assembly [0059] 106a-d Coupling [0060] 107a,b Coupling [0061] 20 Connection pipe [0062] 202 Shut-off valve [0063] 301a,b Transfer line [0064] 302a,b Transfer line [0065] 303a-d Coupling
