DE102018206334A1 - Fuel delivery device for cryogenic fuels - Google Patents

Abstract

Fuel feed device (100) for cryogenic fuels with a tank (30), a high pressure feed pump (1) and a supply line (18), via which feed line (18) of the high pressure feed pump (1) cryogenic fuel from the tank (30) can be supplied. The high-pressure feed pump (1) has a pump housing (2) in which a suction space (50) connected to the feed line (18) is formed, which suction space (50) can be connected to a high-pressure space (12) by means of a connecting channel (26). For opening and closing the connecting channel (26), a suction valve (14) is arranged in the pump housing (2), wherein the suction valve (14) comprises a suction valve element (140) movable along a longitudinal axis (28) of the high-pressure feed pump (1). The suction valve element (140) interacts with a first sealing seat (25), wherein a cold-shunt valve element (66) is arranged coaxially to the suction valve element (140), on which cold-shunt valve element (660) the first sealing seat (25) is formed. In addition, both the cold shuttle valve element (660) and the suction valve element (140) are in each case designed as a magnet armature (66 ', 140') which can be lifted by means of an electromagnet (6).

Description

The invention relates to a fuel delivery device for cryogenic fuels. This fuel delivery device is used, for example, in internal combustion engines of motor vehicles with a cryogenic fuel drive, in particular with natural gas.

State of the art

In the not pre-published font DE 10 2017 219 784 A1 is a fuel conveyor for cryogenic fuels described. The fuel delivery device comprises a prefeed pump and a high-pressure pump. Furthermore, the high-pressure pump has a pump head, in which a compression space is formed, which is limited by a reciprocating piston. In addition, a cold running valve is integrated in the high-pressure pump, via which the compression space and / or a low-pressure chamber of the high-pressure pump is or can be connected to a tank.

If the high-pressure pump is put back into operation after a break in operation, it typically has ambient temperature. However, the cryogenic fuel from the tank has a storage temperature of, for example, -160 ° C, so that it immediately evaporates when pumped into the pump head of the high-pressure pump. Therefore, in the high pressure pump the DE 10 2017 219 784 integrated a cold run valve, whereby the compression space and / or the low-pressure space is connectable to the tank, so that the pump head of the high pressure pump can be flushed with cryogenic fuel before start-up, in order to pre-cool this for operation.

Advantages of the invention

The fuel delivery device according to the invention with the characterizing features of claim 1 has the advantage that in a simple and cost-effective manner, the function of the cold-off valve is integrated into the low-pressure accumulator, without affecting the function of the high-pressure pump.

For this purpose, the fuel delivery device for cryogenic fuels to a tank, a high-pressure pump and a supply line, via which supply line of the high-pressure pump cryogenic fuel from the tank can be fed. The high-pressure feed pump has a pump housing in which a suction space connected to the feed line is formed. The suction chamber is connectable by means of a connecting channel with a high-pressure chamber, wherein a suction valve is arranged in the pump housing for opening and closing the connecting channel. The suction valve comprises a suction valve element which is movable along a longitudinal axis of the high-pressure feed pump and which cooperates with a first sealing seat. Furthermore, coaxial with the suction valve element, a cold drive valve element is arranged, on which cold drive valve element of the first sealing seat is formed. In addition, both the cold-shut valve element and the suction valve element are each designed as a lifting magnet by means of an electromagnet.

Thus, in a simple manner, a cold-driving valve can be integrated in a space-optimized manner for purging the high-pressure feed pump into the high-pressure feed pump without impairing its function or the service life of the components used. Furthermore, the function of the cooling is improved, since in addition to the hydraulic pressure of the cryogenic fuel, the magnetic force of the electromagnet ensures a fast opening stroke of the Saugventilelements.

In a first advantageous embodiment, it is provided that an anchor plate of the cold-vehicle valve element is operatively connected to the electromagnet. Thus, the stroke movement of the cold retard valve element can be precisely controlled by means of the electromagnet.

In a further embodiment of the invention, it is advantageously provided that the suction valve element has longitudinal grooves through which longitudinal grooves with open first sealing seat cryogenic fuel from the suction chamber can flow into the high-pressure chamber. Thus, a flow of cryogenic fuel in the high-pressure feed pump can be made possible in a simple and space-saving manner.

In an advantageous embodiment, it is provided that the cold drive valve element has a recess in which recess a spring is arranged, which spring is supported between the cold drive valve element and the suction valve element and the suction valve element is acted upon by a force in the direction of the first sealing seat. Advantageously, the connecting channel is formed in the recess of the cold-actuated valve element and the suction valve is received in the recess of the cold-actuated valve element. Thus, the cold shuttle valve element can be integrated into the high-pressure feed pump in a simple manner, without requiring additional space.

In a further embodiment of the invention, it is advantageously provided that the suction valve element has an anchor plate, on which anchor plate projections are formed, which projections are engageable in recesses of the anchor plate of the cold shuttle valve element. Through optimized Spatial arrangement of the anchor plate of the suction valve element to the electromagnet can be increased in a simple manner, the magnetic force on the suction valve element, so that a faster switching is achieved.

In an advantageous embodiment, a second sealing seat is formed on a conically tapered shoulder of the pump housing, which cooperates with the cold-driving valve element for opening and closing a connection between the high-pressure chamber and the return line and thus forms a cold running valve. Thus, in a simple manner, the return of cryogenic fuel from the high-pressure pump is ensured in the direction of the tank.

In a further embodiment of the invention, it is advantageously provided that the cold drive valve element is acted upon by means of a compression spring with a force in the direction of the second sealing seat. As a result, the connection between the high-pressure chamber and the return line can be closed.

In an advantageous embodiment, the first sealing seat is conical. Thus, an improved function of the suction valve in the high-pressure delivery pump and thus an optimization of the tightness at the first sealing seat is achieved.

In a further embodiment of the invention, it is advantageously provided that the high-pressure chamber is connectable to a return line, which is connected to the tank. As a result, a fuel circuit between the high-pressure feed pump and the tank is closed when opening the return line.

In an advantageous embodiment, it is provided that in the longitudinal bore a longitudinally movable pump piston is arranged, which limits the high-pressure chamber. Advantageously, the pump piston is acted upon by means of a spring with a force against the direction of the suction chamber. By longitudinal movements of the pump piston, the cryogenic fuel can be compressed during operation and promoted by the high pressure pump.

In an advantageous embodiment, it is provided that in the tank, a prefeed pump is arranged, which promotes fuel from the tank via the supply line into the suction of the high pressure pump. This allows a variable arrangement of the high-pressure feed pump, so that it can be arranged, for example, relatively close to the tank container, or relatively close to the internal combustion engine.

list of figures

• 1a ein Ausführungsbeispiel einer erfindungsgemäßen Kraftstofffördereinrichtung im Längsschnitt,
• 1b das Ausführungsbeispiel der erfindungsgemäßen Kraftstofffördereinrichtung aus der 1a mit geöffneten Ventilen im Längsschnitt,
• 2a ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Kraftstofffördereinrichtung im Längsschnitt,
• 2b das Ausführungsbeispiel der erfindungsgemäßen Kraftstofffördereinrichtung aus der 2a mit geöffneten Ventilen im Längsschnitt.

In the drawings, embodiments of a fuel delivery device according to the invention are shown. It shows

• 1a an embodiment of a fuel delivery device according to the invention in longitudinal section,
• 1b the embodiment of the fuel delivery device according to the invention from the 1a with opened valves in longitudinal section,
• 2a a further embodiment of a fuel delivery device according to the invention in longitudinal section,
• 2 B the embodiment of the fuel delivery device according to the invention from the 2a with opened valves in longitudinal section.

Description of the embodiments

In the 1a is an embodiment of a fuel delivery device according to the invention 100 for cryogenic fuel, for example natural gas, shown in longitudinal section. The fuel conveyor 100 has a tank 30 , a high pressure pump 1 and a supply line 18 on which the tank 30 with the high pressure pump 1 combines.

The Tank 30 is used to store the cooled down to a temperature of, for example -110 ° C or less fuel. The tank points to this 30 an inner tank 301 and an outer tank 302 on, which through a gap 303 are separated. The gap 303 is usually evacuated, leaving only a very low heat input from the environment into the tank 30 can be done. The inner tank 301 is up to a fill level 51 with liquid portion 32 filled the fuel. Above the fill level 51 the fuel is in its gaseous phase 31 in front.

The Tank 30 is from a pre-feed pump 34 intersperses which the fuel from the tank 30 via the supply line 18 in the direction of the high pressure pump 1 promotes. It is in the supply line 18 a shut-off valve 44 arranged, which when not operated fuel conveyor 100 closed to a backflow of gaseous fractions 31 of the fuel from the high pressure pump 1 in the tank 30 to prevent. The Tank 30 also includes a pressure relief valve 45 , so that when exceeding a maximum limit pressure in the tank 30 Gas can be discharged to the environment.

The high pressure pump 1 has a pump housing 2 in which a stepped longitudinal bore 17 is trained. In the longitudinal bore 17 is a longitudinally movable pump piston 4 arranged. With an end 46 limited the pump piston 4 a high pressure room 12 , which with a pipe 16 by means of a pressure relief valve 52 can be connected to a high-pressure accumulator. Furthermore, the high pressure room 12 via a return line 22 with the tank 30 connectable.

Furthermore, in the longitudinal bore 17 a suction chamber 50 formed, which with the supply line 18 is connected and from which a connection channel 26 in the high pressure room 12 empties. In the suction room 50 is a longitudinally movable suction valve element 140 arranged, which with a plate-shaped end 54 in the high pressure room 12 protrudes. The suction valve element 140 is of a cold shuttle valve element 660 surrounded, at which a first sealing seat 25 is trained. This first sealing seat 25 forms together with the suction valve element 140 a suction valve 14 out.

In the suction room 50 is still an electromagnet 6 arranged, which has a magnetic core 60 and a magnetic coil 600 includes. The cold shuttle valve element 660 is here as magnet armature 66 ' with an anchor plate 38 educated. Together with one on a conically tapered heel 20 of the pump housing 2 trained second sealing seat 27 forms the cold shuttle valve element 660 a cold shut-off valve 66 out. By means of a compression spring 3 which is located between the anchor plate 38 the cold shuttle valve element 660 and a paragraph 36 of the pump housing 2 is supported, is the cold shuttle valve element 660 with a force in the direction of the second sealing seat 27 applied.

Furthermore, the cold shuttle valve element 660 a recess 29 on, in which the suction valve element 140 is included. The suction valve element 140 is also here as a magnet armature 140 ' formed and has an anchor plate 39 on, on which a spring 5 supports, which the suction valve element 140 with a force in the direction of the first sealing seat 25 charged so that the suction valve 14 with its plate-shaped end 54 the first sealing seat 25 locks. In the suction valve element 14 are longitudinal grooves 55 formed, wherein the connecting channel 26 between the suction valve element 140 and the cold shuttle valve element 660 in the longitudinal grooves 55 and the recess 29 the cold shuttle valve element 660 is trained.

With his intake 50 opposite end limits the pump piston 4 together with the pump housing 2 a control room 48 , where the fuel pressure in the control room 48 over a canal 8th is degradable. Furthermore, in the control room 48 a feather 47 arranged, which the pump piston 4 in the direction of an opening 58 with force. The opening 58 is doing with a hydraulic system, not shown, for driving the high-pressure pump 1 connected.

The anchor plate 38 the cold shuttle valve element 660 and the anchor plate 39 of the suction valve element 140 are in the pump housing 2 with the electromagnet 6 operatively connected, what follows through the functioning of the fuel conveyor 100 will be shown.

Operation of the fuel conveyor

During operation of the fuel delivery device 100 promotes the pre-feed pump 34 Fuel from the tank 30 via the supply line 18 in the direction of intake 50 the high-pressure pump 1 , where the electromagnet 6 is not switched on in this operating mode. By longitudinal movements of the suction valve element 140 and the pump piston 4 the fuel is in the high pressure pump 1 promoted. At the same time the pump piston moves 4 in the direction of the opening 58 , whereby in the high-pressure space 12 the pressure drops, leaving the suction valve 14 the connection channel 26 releases and cryogenic fuel from the high-pressure chamber 12 in the suction room 50 can flow. This reduces the pressure in the high-pressure chamber 12 , so that the pressure at the end portion of the pump piston 4 which is the high pressure room 12 is not as high as at the other end of the pump piston 4 , Due to this, the pump piston moves 4 again in the direction of the opening 58 and the suction valve 14 closes the connection channel 26 , As a result, the cryogenic fuel is compressed to an addressed system pressure of, for example, 500 bar and via the pressure relief valve 52 into the pipe 16 pressed. The compressed fuel can be supplied to injection valves of an internal combustion engine, for example.

Upon initial operation or resumption of operation of the fuel delivery system 100 becomes the high pressure pump 1 flushed with cryogenic fuel to cool it and evaporation of the cryogenic fuel immediately after entering the high pressure feed pump 1 to prevent and prevent possible losses.

1b shows the embodiment of the fuel delivery device according to the invention 100 from the 1a in longitudinal section with open suction valve element 140 and opened cold shuttle valve element 660 ,

For opening the second sealing seat 27 becomes the magnetic coil 600 energized and thus generates a magnetic field, which acts both as the magnet armature 66 ' trained cold shuttle valve element 660 as well as on the magnet armature 140 ' trained suction valve element 140 exerts a magnetic force. Is this magnetic force greater than the spring force of the compression spring 3 and the spring 5 , so the cold shuttle valve element moves 660 in the direction of the pump piston 4 and gives the second sealing seat 27 free and the suction valve element 140 gives the first sealing seat 25 free. So is a fuel circuit between the tank 30 and the high pressure feed pump 1 closed, the pump piston 4 does not perform any longitudinal movement during flushing. Cryogenic fuel now flows over the supply line 18 in the suction room 50 and from there via the connection channel 26 in the high pressure room 12 , About the released second sealing seat 27 the cryogenic fuel flows over the return line 22 in the tank 30 back.

So can the high pressure pump 1 upon initial operation or resumption of operation of the fuel delivery device 100 are cooled to operating temperature by flushing with cryogenic fuel and there are no losses during commissioning such as by evaporation of the cryogenic fuel immediately after entering the high-pressure pump 1 , Moreover, by the through the electromagnet 6 also controllable suction valve element 140 a fast and efficient flushing possible, at the same time a possibly occurring wear on the suction valve element 140 , For example, by rebuffing of the suction valve element 140 at the first sealing seat 25 , can be minimized.

2a shows a further inventive embodiment of the fuel delivery device 100 in longitudinal section. Components of the same function have been designated by the same reference number. The further embodiment largely corresponds in function and structure to the first embodiment of the 1a and 1b , The difference lies in the designs of the anchor plates 38 . 39 of the suction valve element 140 and the cold shuttle valve element 660 , The anchor plate 38 the cold shuttle valve element 660 has several recesses 40 on, in which recesses 40 the anchor plate 39 of the suction valve element 140 with moldings 37 can intervene. So can the spatial distance between the anchor plate 39 of the suction valve element 140 and the electromagnet 6 minimizes and the magnetic force on the suction valve element 140 with active electromagnet 6 increase.

2 B shows the further embodiment of the invention the fuel conveyor 100 from the 2a in longitudinal section with open suction valve element 140 and opened cold shuttle valve element 660 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102017219784 A1 [0002]
• DE 102017219784 [0003]

Claims (13)

Fuel feed device (100) for cryogenic fuels with a tank (30), a high-pressure feed pump (1) and a feed line (18), via which feed line (18) of the high-pressure feed pump (1) cryogenic fuel from the tank (30) can be supplied, wherein the High-pressure feed pump (1) has a pump housing (2) in which a with the supply line (18) connected to the suction chamber (50) is formed, which suction chamber (50) by means of a connecting channel (26) with a high-pressure chamber (12) is connectable, wherein the Opening and closing the connecting channel (26) a suction valve (14) in the pump housing (2) is arranged, wherein the suction valve (14) along a longitudinal axis (28) of the high-pressure feed pump (1) movable suction valve element (140) comprises, which with a cooperates with the first suction seat (25), wherein coaxial with the suction valve element (140) a cold shuttle valve element (66) is arranged on which cold-driving valve element (660) of the first sealing seat (25) is, wherein both the cold shuttle valve element (660) and the suction valve element (140) each as by means of an electromagnet (6) liftable magnet armature (66 ', 140') is formed. Fuel conveyor (100) according to Claim 1 , characterized in that the cold shuttle valve element (660) forms an armature plate (38) which is operatively connected to the electromagnet (6). Fuel conveyor (100) according to Claim 1 or 2 , characterized in that the suction valve element (140) has longitudinal grooves (55) through which longitudinal grooves (55) with open first sealing seat (25) cryogenic fuel from the suction chamber (50) in the high-pressure chamber (12) can flow. Fuel conveyor (100) according to Claim 1 . 2 or 3 , characterized in that the cold driving valve element (660) has a recess (29), in which recess (29) a spring (5) is arranged, which spring (5) is supported between the cold driving valve element (660) and the suction valve element (140) and the suction valve element (140) is acted upon by a force in the direction of the first sealing seat (25). Fuel conveyor (100) according to Claim 4 , characterized in that the connecting channel (26) formed in the recess (29) of the cold-driving valve element (660) and in the recess (29) of the cold drive valve element (660), the suction valve (14) is accommodated. Fuel conveyor (100) according to Claim 2 , characterized in that the suction valve element (140) has an anchor plate (39) on which anchor plate (39) projections (37) are formed, which projections (37) in recesses (40) of the anchor plate (38) of the cold shuttle valve element (660) are engageable. Fuel delivery device (100) according to any one of the preceding claims, characterized in that on a conically tapered shoulder (20) of the pump housing (2) a second sealing seat (27) is formed, which with the cold drive valve element (660) for opening and closing a connection between the high-pressure chamber (12) and the return line (22) cooperates and so a cold driving valve (66) is formed. Fuel conveyor (100) according to Claim 7 , characterized in that the cold driving valve element (660) by means of a compression spring (3) is acted upon by a force in the direction of the second sealing seat (27). Fuel delivery device (100) according to one of the preceding claims, characterized in that the first sealing seat (25) is conical. Fuel delivery device (100) according to one of the preceding claims, characterized in that the high-pressure chamber (12) is connectable to a return line (22) which is connected to the tank (30). Fuel delivery device (100) according to any one of the preceding claims, characterized in that in the longitudinal bore (17) a longitudinally movable pump piston (4) is arranged, which limits the high-pressure chamber (12). Fuel conveyor (100) according to Claim 11 , characterized in that the pump piston (4) by means of a spring (47) with a force against the direction of the suction chamber (50) is acted upon. Fuel delivery device (100) according to any one of the preceding claims, characterized in that in the tank (30) a prefeed pump (34) is arranged, which fuel from the tank (30) via the supply line (18) into the suction chamber (50) of the high pressure feed pump (1) promotes.

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