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(11) | EP 1 150 006 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Arrangement for locating fuel leakage in connection with a combustion engine |
| (57) In an arrangement for locating fuel leak in connection with a large combustion engine
(5), particularly a large diesel engine, fuel is fed into several fuel injectors (8)
from a common fuel space (9, 10), and a fuel injection system comprises a double wall
(15) fuel pipe system (11, 12, 3), which in turn comprises an inner flow space (14)
for fuel and outer flow space (16) for possibly leaking fuel. The fuel injection system
comprises at least one leaking fuel detection arrangement (18, 18', 18", 18"') in
connection with an outer flow channel (16) of at least one section of the pipe system
(11, 12, 13). |
[0001] The present invention relates to an arrangement for locating a fuel leak in connection with a large combustion engine, particularly a large diesel engine, according to the preamble of claim 1, in which combustion engine fuel is fed into several fuel injectors from a common fuel space, and in which a fuel injection system comprises a double wall fuel pipe system, which in turn comprises an inner flow space for fuel and an outer flow space for possibly leaking fuel.
[0002] The expression "large combustion engine" in this context means an engine such as those which may, for example, be used as main or auxiliary engines of ships or in power plants for production of heat and/or electricity.
[0003] It is commonly known to arrange the fuel pipes of a diesel engine inside another pipe shell in order to keep possible leakage inside the outer shell. In the case of a leak, the leaking fuel may be carried along inside the outer shell away from the vicinity of the engine. In order to detect the leak in this kind of solution e.g. different kinds of plugs have been used. Thus the leak could be detected by unplugging the plug. Another method has been to utilise disengageable hoses: by disconnecting these, a leak could also be detected. This known method is, however, very unsophisticated, because the locating of a leak by this method is very slow and also troublesome. The hoses and/or plugs must be disconnected one after the other until the leaking location is eventually found.
[0004] It is an aim of the invention to provide a new arrangement for locating a fuel leak, which makes possible fast fuel leak detection as well as systematic locating of the leaking location.
[0005] The present invention provides an arrangement for locating a fuel leak according to claim 1. Preferred or optional features of the invention are defined in the dependent claims. According to the invention the fuel injection system comprises a fuel pipe system provided with double walls. The pipe system comprises an inner flow channel for fuel and an outer flow channel for possibly leaking fuel. Fuel is conveyed by the fuel pipe system from a source of fuel to a fuel injector of each respective cylinder of the combustion engine. The injection system also comprises at least one leaking fuel detection arrangement in connection with an outer flow channel of at least one section of the pipe system. Thus, in the case of a leak, leaking fuel may be conveyed in a closed flow channel to a fuel leak alarm location, in which the occurrence of the leak is registered and necessary actions can be taken.
[0006] According to an embodiment of the invention, the leaking fuel detection arrangement comprises means for selectively connecting or disconnecting the outer flow channels of the pipe system with or from each other. In this manner, each section of pipe system to be inspected may be separated from the rest of the pipe system during the inspection, so that the locating of the leak is efficient.
[0007] According to another embodiment of the invention, the arrangement for locating the fuel leak comprises means for guiding the leaking fuel in the closed flow channel of the pipe system selectively forward or out of the pipe system for locating the leak.
[0008] According to still another embodiment of the invention the arrangement for locating the fuel leak comprises a configuration in which the fuel pipe system is branched. The outer flow channels of several branch pipes are connectable to an outer flow channel of a common fuel supply pipe feeding fuel to the branch pipes or respectively to a common leaking fuel discharge flow channel. In this manner, a possible leak can be detected in a centralised way and the locating of the leak may be accomplished very systematically.
[0009] The fuel injection system preferably comprises at least one pressure accumulator unit provided with the leaking fuel detection arrangement, the pressure accumulator unit comprising connecting channels arranged in the pressure accumulator. The connecting channels are selectively connectable to outer flow channels of fuel pipe sections connected to pressure accumulator unit. At least one action means may be provided in connection with the or each pressure accumulator unit, the operation of the leaking fuel detection arrangement being governed by co-operative action of said action means and/or said connecting channels. The outer flow channels of fuel supply pipes and fuel delivery pipes are selectively connectable with the outer flow channel of fuel connection pipes.
[0010] An action means according to a certain embodiment of the invention comprises an annular device surrounding the pressure accumulator unit. The pressure accumulator unit includes flow channels capable of being selectively connected with the connecting channels by rotating the annular device, by co-operative action of which the flow of leaking fuel may be guided in the outer flow channel forward or out of the pipe system for locating the leak.
[0011] An action means according to another embodiment of the invention comprises a screw, pin or the like provided in connection with a wall of the pressure accumulator unit and its connection pipes. The position of the action means in relation to the pressure accumulator and the connecting channels is changeable. Based on said position, flow spaces for the leaking fuel are connectable or disconnectable with each other for guiding the leaking fuel selectively forward in the outer flow space of the fuel pipe system.
[0012] The position of the action means in relation to the pressure accumulator may also be arranged to be changed by the effect of the pressure of the leaking fuel.
[0013] The fuel detection arrangement according to the invention is particularly suitable for a fuel injection system which comprises a high pressure pump, by means of which fuel may be fed to a pressure supply comprising at least one pressure accumulator unit. The fuel may be further fed from the pressure accumulator unit by means of injectors to cylinders of the engine. In the system the fuel supply pipes interconnect the high pressure pump and the pressure supply, fuel delivery pipes interconnect the pressure accumulator units and the injectors, and a fuel connection pipe possibly interconnects several pressure accumulator units with each other. Thus, at least fuel supply pipes, fuel delivery pipes and fuel connection pipes comprise pipes provided with a double wall. According to the invention the outer flow spaces are preferably selectively connectable with or disengageable from each other by means of at least one fuel leak detection arrangement in connection with the outer flow space of the pipe system. The fuel pipe system is branched at the pressure accumulator unit, whereas the outer flow channels of several branch pipes are connectable with an outer flow channel of a common fuel supply pipe feeding fuel to the branch pipes or in some cases with a common leaking fuel outlet flow channel. In this way, a possible leak may be centralised and guided forward and is further detectable.
[0014] According to still another embodiment of the invention the fuel connection pipe of the fuel injection system is provided with a partition wall or the like, by means of which the outer flow channel is divided into two compartments. One of the compartments has a pressure accumulator unit and injectors connected thereto as well as a fuel pump and the other compartment has another pressure accumulator unit and injectors connected thereto as well as fuel pump. Both of the compartments are connected with a leaking fuel detection arrangement, which comprises means for selectively guiding the flow of leaking fuel forward in a separate discharge flow channel to a leaking fuel alarm device or out of the flow space for locating the leak. In this manner it is possible to find out in a very safe and assured manner from which pipe or from which pipe section the leaking fuel is coming by means of the leaking fuel detection arrangement. The arrangement may also comprise two or several injection systems connected with each other by means of fuel connection pipes.
[0015] The invention provides several advantages. The operational security of the engine is clearly better and on the other hand, the locating of leaking fuel is achieved in a safe manner. Additionally the leaking area may be isolated from the remainder of the pipe system and thus the locating of the leak is faster than by using known solutions.
[0016] The invention will be described by way of example with reference to the appending drawings, in which
- Figure 1 shows schematically an arrangement for locating a fuel leak according to the invention,
- Figure 2 shows schematically a checking mode of operation of the arrangement for locating a fuel leak,
- Figure 3 shows schematically a normal mode of operation of the arrangement for locating a fuel leak according to Figure 2,
- Figure 4 shows schematically a normal mode of operation of another arrangement for locating a fuel leak,
- Figure 5 shows schematically a checking mode of operation of the arrangement for locating a fuel leak according to Figure 4,
- Figure 6 shows a connection ring of the arrangement for locating a fuel leak according to Figures 4 and 5.
- Figure 7 shows schematically another embodiment of the arrangement for locating a fuel leak according to an implementation of the invention in its normal mode of operation,
- Figure 8 shows the embodiment of Figure 7 in its checking mode of operation,
- Figure 9 shows schematically still another embodiment of the arrangement for locating fuel leak according to an implementation of the invention in its checking mode of operation, and
- Figure 10 shows the embodiment of Figure 9 in its normal mode of operation.
[0017] Figure 1 schematically shows a section of a fuel injection system 1 of a large combustion engine 5, particularly a large diesel engine. The combustion engine 5 has been illustrated in this context very schematically for clarity's sake, and it may be a commonly known large combustion engine. In Figure 1, the cylinders and cylinder heads 7 are shown in a slightly more detailed manner. Fuel is fed from a fuel tank 2 by means of a fuel pump 3 through a fuel pipe system 4 to each high pressure pump 6, which in turn elevates the pressure of the fuel to such a level, that sufficient injection pressure may be obtained at the injectors 8. The high pressure pump is in connection with a pressure supply 10, which comprises at least a pressure accumulator unit 9, into which fuel is fed by the high pressure pump 6. Fuel is fed from the pressure accumulator unit 9 further to injectors 8 through fuel delivery pipes 11. The fuel injection system preferably comprises an assembly in which fuel is fed by means of a high pressure pump 6 to the pressure supply 10, which comprises at least two separate pressure accumulator units 9, and from which fuel is further fed into the cylinders of the engine 5 by means of injectors 8. Each of the pressure accumulator units 9 is connected to at least two injectors 8 and is provided with a high pressure pump 6 of its own. Fuel supply pipes 12 interconnect the high pressure pump 6 and the pressure supply 10, fuel delivery pipes 11 interconnect the pressure accumulator units 9 and the injectors 8, and fuel connection pipes 13 interconnect the pressure accumulator units 9 with each other. At least the fuel supply pipes 12, delivery pipes 11 and fuel connection pipes 13 are provided with double walls 15, the outer flow spaces 16 of which are connectable with each other. In this manner, in the case of a leak at any location in the system the leaking fuel can be carried along the outer flow space 16 and a discharge flow channel 23 until the leaking fuel is detected at a fuel leak alarm device 17. In order to locate the fuel leak location, the fuel connection pipe 13 is provided with at least one leaking fuel detection arrangement 18 in connection with an outer flow channel 16 of the pipe system. For detecting a leak, the leaking fuel detection arrangement 18 comprises means for selectively connecting or disengaging the outer flow channels of the pipe system with or from each other.
[0018] The fuel connection pipe 13 of the fuel injection system interconnecting the pressure accumulator units 9 is provided with a partition wall 19 or the like, by means of which the outer flow channel 16 is divided into separate compartments, of which two pieces are shown here. One of the compartments has a pressure accumulator unit and injectors connected thereto, as well as a fuel pump, and the other compartment has another pressure accumulator unit and injectors connected thereto as well as fuel pump. The outer flow channel 16 of both of the compartments is connected with a leaking fuel detection arrangement 18. The fuel detection arrangement 18 connected to the fuel connection pipe 13 is not, however, always necessary, as in some fuel feeding systems and engines the locating of the leak may be accomplished mainly by fuel detection arrangements 18', 18" or 18''' provided in connection with the pressure accumulator units 9 only.
[0019] Figures 2 and 3 show two different mode of operation of the leak detection arrangement 18 provided in connection with the fuel connection pipe. The leak detection arrangement 18 comprises a body-part 20, in which inlet flow channels 21a, 21b are arranged. The inlet flow channels 21a, 21b are connected with outer flow space 16 of respective compartments. The leaking fuel detection arrangement 18 further comprises an outlet flow channel 23 for guiding possible leaking fuel to the fuel alarm device 17, as well as connecting means 24 provided between each inlet flow channel 21a, 21b and outlet flow channel 23. The connecting means serve to connect or disconnect flow either between inlet flow channel 21a, 21b and outlet flow channel 23 or between inlet flow channel 21a, 21b and leak detection channel 22a, 22b. The connecting means 24 are movable between different connection positions, for example by means of threads, when the connecting means 24 are rotated. In normal situation the connection means 24 are at a position shown in Figure 3 i.e. at an outer position, in which possibly leaking fuel may flow from inlet flow channels 21a, 21b via outlet flow channels 23 down to leak alarm device 17. The connecting means are provided with a means, such as gasket 25, for ensuring that possibly leaking fuel flows to the outlet flow channel in the situation shown in Figure 3, and is thus further detectable at the leak alarm device 17, and on the other hand also that in the checking mode of operation the flow connection is only between a pipe section to be checked and the leak detection channel 22a, 22b.
[0020] This kind of leak detection arrangement of different compartments may also be called a pre-detection arrangement, because it firstly enables a systematic survey of leaking compartments.
[0021] When a leak has been registered at leak alarm device 17, the following actions are taken in order to locate the leak. In the case of Figure 1 each connecting means 24 in the leak detection arrangement 18 is moved in turn into the checking position shown in Figure 2, by rotating the connecting means 24. In this way information is obtained, as to in which compartment(s) of the fuel injection system the leak is located. This may be shown as a light leaking fuel flow from the leak detection channel 22a, 22b. The connecting means 24 has been designed such that in the position of Figure 3 the gasket 25 is at a position in which leaking fuel may not flow into outlet flow channel 23 and that possible leaks from other compartments in connection with the detection arrangement may not flow into the leak detection channel 22a, 22b of the compartment in question. In this way it is possible to find the section, the compartment or several compartments of the fuel injection system, in which a leak is occurring in an accurate and safe manner. In the case of a system in which there are no leaking fuel detection arrangements 18 provided in the fuel connection pipes, the locating of leak may be accomplished mainly by leaking fuel detectors 18', 18", 18"' provided in connection with pressure accumulator units 9 only, as will be later explained.
[0022] According to the invention the fuel injection system includes also intra-compartment fuel leak detection arrangements 18', 18", 18''', so called group detection arrangements, preferably so that each distinct fuel pipe system section is provided with a detection arrangement of its own. According to the arrangement of Figure 1, fuel detection arrangements 18' have been arranged in connection with pressure accumulator units 9. These will now be explained with reference to the Figures 4-6, in which an advantageous embodiment of providing leaking fuel detection arrangements in connection with pressure accumulator units is shown.
[0023] Figures 4 and 5 show fuel delivery pipes 11a, 11b, provided with a double wall 15, which run between the injectors and the pressure accumulator unit 9 and are connected to the high pressure volume v of the latter. A fuel supply pipe 12a, provided with a double wall 15, runs between the pressure accumulator unit and the high pressure pump 6. The outer flow space 16 is arranged between the flow pipe and the double wall in order to guide possibly leaking fuel away from the engine's immediate vicinity. Connection channels 31 provided in the pressure accumulator units comprise the leaking fuel detection arrangement 18', the operation of which is governed by co-operative action of a separate action means and/or connection channels 31. In connection with the pressure accumulator unit a connection ring 26 is provided, comprising channels and grooves, by means of which the following operation may be accomplished. The ring-like means i.e. the connection ring 26 comprises flow apertures 27, 28 to be brought into connection with connection channels of the pressure accumulator unit by rotating the ring. By means of the flow apertures the flow of the leaking fuel may be guided forward in the outer flow channel of the fuel pipe system or out of the pipe system for locating the leak. In the normal situation the connection ring is at position A-A (Figure 6), which corresponds to Figure 4. Thus the outer flow channels of the fuel pipes 11a, 11b, 12a are connected by a groove or corresponding channel 27 of the connection ring 26 with a channel 31 in pressure accumulator unit 9, through which the flow of leaking fuel is guided in the outer flow channel of the fuel pipe system further forward to leak alarm device 17. As can be seen from Figures 4 and 5 it is possible to have a corresponding arrangement with suitable channels 31 also for locating leaks of the gaskets 30 of the pressure accumulator unit 9 itself. So, the leaking fuel detection arrangement 18' comprises a branched fuel pipe system, in which the outer flow channels 16 of several branches are connected with an outer flow channel of a common fuel supply pipe 12 feeding fuel to the branch pipes. In this manner, it is possible to accomplish a very effective centralised leak detection. This embodiment is very convenient in connection with a so called common rail fuel injection system, because the fuel leak detection arrangement may be integrated with the pressure accumulator unit.
[0024] The connection ring is rotated from a position A-A of Figure 4 to a position B-B (Figure 6) shown in Figure 5 as follows. A locking screw 29 or the like is unscrewed, so that the connection ring may be rotated. In order to define the positions A-A and B-B the connection ring is provided with a guide pin 39 or the like, the end of which extends into a space 40 limiting the movement of the ring, so that the extreme positions correspond to the positions A-A and B-B. Now, in position B-B, it is possible to find the flow of leaking fuel in the leak detection channel 28, in connection with the leaking pipe. A groove or corresponding channel 27 and a leak detection channel 28 are provided for each fuel pipe connected to the pressure accumulator unit in order to connect the outer flow channel to the outer flow channel of the adjacent pipe sections and to the leak. Four such couples are shown in Figure 6. When the leak has been located the connection ring may be returned to position A-A.
[0025] Figures 7 and 8 show still another embodiment of the leaking fuel detection arrangement 18" according to the invention. In Figures 7 and 8 the delivery pipes 11a, 11b, 11c connecting the injectors and the pressure accumulator unit and provided with double wall 15, are connected to the pressure accumulator unit 9 and its high pressure volume v. Thus the outer flow channel 16 is provided between the flow pipe and the double wall for guiding possibly leaking fuel away from the immediate vicinity of the engine. The pressure accumulator unit is provided with connection channels 31, 31', which together with action means 32, 32' form the leak detection arrangement 18". In this embodiment a suitably machined screw 32, 32' is adapted in connection with connection channels. In the normal mode of operation shown in Figure 7 all of the outer flow spaces are in connection with each other. This is accomplished by a flow space 33 arranged in the screw 32, 32' which together with the connection channel guides the flow of leaking fuel in a certain direction. In this situation possibly leaking fuel is firstly carried to a space formed between the gasket 30 and the body-parts of the pressure accumulator unit 9 and from the space further via the screw 32' and the connection channel 31' to the leak alarm device 17. In Figures 7 and 8 the flow space 33 of the screws 32, 32' is arranged to shut off the outer flow channel of the pipe section under control of the screw from the other outer flow space, as can be seen from Figure 8, in which the screws are shown as opened in the checking mode of operation. Thus, possibly leaking fuel from each different section may flow out through a groove 34 provided into the body-part and the leak may be ascertained independently from other possible leaks.
[0026] As also shown in Figures 7 and 8, the fuel leak detection arrangement 18" may be adapted to operate so that when the fuel pipe system is branched, as in this case, viz. fuel delivery pipes 11a, 11b, 11c, the outer flow channels 16 of the delivery pipes are connected with a common leaking fuel outlet channel 31'. Thus, when the leak alarm device 17 provides advice of a leak, it is possible, in the case shown in Figures 7 and 8, to open the screw 32", which guides out possibly leaking fuel flow from all delivery pipes of this pressure accumulator unit along the groove 34 provided into the body, whereas it may be centrally found out if there is any leak at all in this section. Thus, the leaking fuel detection arrangement 18" comprises a system wherein the fuel pipe is branched and the outer flow spaces 16 of several fuel pipe branches are in connection with a leaking fuel outlet channel 31' common to these branches. In this way it is possible to obtain a very effective centralised leak detection.
[0027] Figures 9 and 10 show still a further embodiment of leaking fuel detection arrangement according to the invention. These show as an example a detail for locating a leak from fuel pipe 11a, but this may also be applied respectively to locating leaks in gaskets 30 of pressure accumulator unit 9. In this embodiment, there is a pin 35 and a suitable housing 36 as well as a spring loaded ball 37or the like, arranged in connection with the outer flow channel 16 in the pressure accumulator unit 9. Figure 10 shows a normal situation, in which there is no leak and the pin is in its inner position in the housing 36. Normally all the outer flow spaces in this embodiment are divided from each other. The pins remain in this position regardless of the fact that the components typically vibrate, because the spring loaded ball 37 or the like keeps the pin in its position by means of a groove or the like (not shown) arranged in the pin, and co-operating with the ball or the like. If a leak takes place for example in the pipe 11a, pressure begins to rise in the pressure space 38 of the pin housing. By proper design of the spring loaded ball 37or the like and the co-operating groove or the like, it is possible to set a pressure in the pressure space 38, at which the pin begins to move outwards in the pin housing 36, until the situation shown in Figure 9 is reached, in which the leak may flow away to the leak alarm device 17. Thus, the pin operates as an action means provided in connection with a wall of the pressure accumulator unit, the position of which means may be changed by the pressure of the leaking fuel, and the position of which in relation to the pressure accumulator unit governs the flow of the leaking fuel in the outer flow space of the fuel pipe system for detection of the leak. In this embodiment no fuel emerges even at the locating stage, but the leak is detected by the pin extending from the body.
[0028] The embodiments of leaking fuel detection arrangement described above have been illustrated as independent, but it is possible to incorporate several basic solutions operating according to different embodiments into the same engine. In the context of the present invention it is also possible to connect the operation of different embodiments that have been described.
1. An arrangement for locating a fuel leak in connection with a large combustion engine
(5), particularly a large diesel engine, in which fuel is fed into several fuel injectors
(8) from a common fuel space (9, 10), and in which a fuel injection system comprises
a double wall (15) fuel pipe system (11, 12, 13), which in turn comprises an inner
flow space (14) for fuel and an outer flow space (16) for possibly leaking fuel, characterised in that the fuel injection system comprises at least one leaking fuel detection arrangement
(18, 18', 18'', 18''') in connection with an outer flow channel (16) of at least one
section of the pipe system (11, 12, 13).
2. An arrangement according to claim 1, characterised in that the leaking fuel detection arrangement (18, 18', 18'', 18''') comprises means (21,
22, 23, 24, 26, 27, 28, 29, 31, 31', 33, 34, 35) for selectively connecting or disconnecting
outer flow channels of the pipe system with or from each other.
3. An arrangement according to claim 1 or 2, characterised in that the leaking fuel detection arrangement (18, 18', 18") comprises means (21, 22, 23,
24, 26, 27, 28, 29, 31, 31', 33, 34) for guiding the leaking fuel flow out of the
pipe system for locating the leak, or for guiding the leaking fuel flow in a closed
flow channel or in the outer flow channel of the pipe.
4. An arrangement according to any of the preceding claims, characterised in that the fuel injection system comprises at least one pressure accumulator unit (9), in
connection with which the leaking fuel detection arrangement (18, 18,' ,18", 18"')
is arranged and that the leaking fuel detection arrangement (18, 18', 18", 18''')
comprises connecting channels (31, 31') arranged in the pressure accumulator (9),
which connecting channels (31, 31') are selectively connectable to the outer flow
channels (16) of fuel pipe sections connected to pressure accumulator unit.
5. An arrangement according to claim 4, characterised in that the leaking fuel detection arrangement (18, 18,' ,18", 18''') comprises at least
one action means (26, 32, 35) provided in connection with the or each pressure accumulator
unit (9), and that the operation of the leaking fuel detection arrangement (18, 18',
18", 18"') is governed by co-operative action of said at least one action means (26,
32, 35) and/or the connection channels (31, 31').
6. An arrangement according to claim 5, characterised in that the action means (26, 32, 35) comprises an annular device (26), which includes flow
channels (27, 28) capable of being selectively connected with the connecting channels
(31, 31') by rotating the annular device (26), by co-operative action of which the
flow of leaking fuel may be guided in the outer flow channel forward or out of the
pipe system for locating the leak.
7. An arrangement according to claims 5 or 6, characterised in that the action means (26,32,35) comprises a screw, pin or the like (32, 35), the position
of which in relation to the pressure accumulator (9) and the connecting channels (31,
31') is changeable and based on said position the flow spaces for the leaking fuel
are connectable or disconnectable for guiding the leaking fuel selectively forward
in the outer flow space of the fuel pipe system.
8. An arrangement according to claim 7, characterised in that the position of the action means (26, 32, 35) in relation to the pressure accumulator
(9) is arranged to change by the effect of the pressure of the leaking fuel.
9. An arrangement according to claim 1 or 2, including at least two pressure accumulator
units (9) connected by a fuel connection pipe (13), characterised in that the fuel connection pipe (13) is provided with a partition wall (19) or the like,
by means of which the outer flow channel (16) is divided into separate compartments,
one compartment having a pressure accumulator unit (9) and injectors (8) connected
thereto as well as a fuel pump (6) and another compartment having another pressure
accumulator unit (9) and injectors (8) connected thereto as well as fuel pump (6),
and that the outer flow channel (16) of both of the compartments is connected with
a leaking fuel detection arrangement (18), which comprises means (21, 22, 23, 24)
for selectively guiding the flow of leaking fuel forward in a separate discharge flow
channel (23) to a leaking fuel alarm device (17) or out of the flow space for locating
the leak.
10. An arrangement according to claim 9, characterised in that the leaking fuel detection arrangement (18) comprises a body-part (20), in which
inlet flow channels (21a, 21b) are arranged, which inlet flow channels (21a, 21b)
are connected with the outer flow space (16) of respective compartments, an outlet
flow channel (23) for guiding possibly leaking fuel to the fuel alarm device (17),
as well as connecting means (24) for connecting or disconnecting flow either between
the inlet flow channel (21a, 21b) and an outlet flow channel (23) or between the inlet
flow channel and a leak detection channel (22a, 22b).
11. An arrangement according to any of the preceding claims, characterised in that the leaking fuel detection arrangement (18, 18', 18'', 18''') comprises a configuration
in which the fuel pipe system is branched, the outer flow channel (16) of several
branch pipes (11a, 11b, 11c, 11d) being connectable to an outer flow channel (16)
of a common fuel supply pipe (12) feeding fuel to the branch pipes.
12. An arrangement according to any of the preceding claims, characterised in that the leaking fuel detection arrangement (18, 18', 18'', 18''') comprises a configuration
in which the fuel pipe system is branched, the outer flow channel (16) of several
branches (11a, 11b, 11c, 11d) being connectable to a common leaking fuel discharge
flow channel (23, 31').