Heave tolerant pile guiding device for guiding a pile during installation thereof
A heave tolerant pile guiding device for guiding a pile including a cylindrical section and above said cylindrical section a tapered section that narrows in upward direction. The device includes a frame to be mounted to a vessel having a hull subject to sea-state induced motion during installation of a pile. At least one pair of first and second pile engaging devices is arranged on the frame diametrically opposed relative to a center axis. Each pile engaging device comprises a pile engaging member and a hydraulic cylinder to move the member radially relative to the center axis. A hydraulic system includes a position control circuit and a sphincter control circuit. The sphincter control circuit is configured to operate the pair of first and second hydraulic cylinders in particular when the pile engaging members engage on the tapered section of the pile. The sphincter control circuit is a rotary flow divider.
1 . A heave tolerant pile guiding device for guiding a pile during installation thereof, the pile comprising a cylindrical section and above said cylindrical section a tapered section that narrows in upward direction, the pile guiding device comprising:
a frame configured to be mounted to a vessel having a hull that is subject to sea-state induced motion during installation of the pile;
at least one pair of first and second pile engaging devices arranged on the frame diametrically opposed relative to a center axis,
wherein the first pile engaging device comprises a first pile engaging member configured to engage on an exterior of the pile during installation thereof, and a first hydraulic cylinder configured to move the first pile engaging member radially relative to the center axis, and wherein the second pile engaging device comprises a second pile engaging member configured to engage on the exterior of the pile during installation thereof, and a second hydraulic cylinder configured to move the second pile engaging member radially relative to the center axis; and
a hydraulic circuit associated with the pair of first and second hydraulic cylinders,
wherein the hydraulic system comprises a position control circuit configured to operate the pair of first and second hydraulic cylinders on the basis of position control,
wherein the hydraulic system comprises a sphincter control circuit configured to operate the pair of first and second hydraulic cylinders when the pile engaging members engage on the tapered section of the pile,
wherein each of the cylinders comprises a cylinder body with a head and a bottom, a piston and piston rod assembly, the piston protruding from the head of the cylinder body, a variable volume bottom chamber between the bottom and the piston, and a variable volume head chamber between the head and the piston,
wherein the sphincter control circuit comprises:
a first line connected to the bottom chamber of the first cylinder;
a second line connected to the bottom chamber of the second cylinder;
a third line connected to both the head chamber of the first cylinder and the head chamber of the second cylinder;
a rotary flow divider having a first pump device and a second pump device on a common rotary shaft, the first pump device connected to the first line and the second pump device connected to the second line, each of the first and second pump devices being connected to the third line;
an accumulator connected to the third line; and
a valve assembly configured to selectively open and close a connection of the rotary flow divider to the first and second lines, so that, with said connection closed, the cylinders—are operated by the position control circuit,
and so that, with said connection open, a sphincter mode of the hydraulic cylinders is established wherein the first and second hydraulic cylinders are hydraulically pressurized by the accumulator thereby urging the first and second pile engaging members against the tapered section,
and so that, during a downward motion of the pile guiding device relative to the tapered section of the pile, the cylinder bottom chambers expel hydraulic liquid via the first and second lines, respectively, the flow divider causing an equal flow of said expelled hydraulic fluid, some of said expelled hydraulic liquid being fed via the third line to the head chambers of the first and second hydraulic cylinders and some being received by the accumulator,
and so that, during an upward motion of the pile guiding device relative to the tapered section of the pile, the accumulator feeds hydraulic liquid via the flow divider to the bottom chambers of the first and second hydraulic cylinders, the rotary flow divider causing an equal flow of said feeds of hydraulic fluid, the head chambers expelling hydraulic liquid via said third line.
2 . The heave tolerant pile guiding device according to claim 1 , wherein the sphincter control circuit comprises a rotary flow divider with an integrated hydromotor configured for driving the rotary shaft, wherein the hydromotor is arranged in the connection between the accumulator and the third line, so that during said downward motion of the pile guiding device relative to the tapered section of the pile, said expelled hydraulic liquid flowing to the accumulator operates the hydromotor and thereby drives the first and second pumps of the rotary flow divider to cause equal flow,
and so that, during said upward motion of the pile guiding device relative to the tapered section of the pile, hydraulic liquid is fed from the accumulator via the hydromotor to the rotary flow divider and then in equal flows to the bottom chambers of the first and second hydraulic cylinders, the hydromotor driving the first and second pumps of the flow divider to cause equal flow.
3 . The heave tolerant pile guiding device according to claim 2 , wherein the sphincter circuit comprises a boost accumulator connected to the third line between the flow divider and the hydromotor.
4 . The heave tolerant pile guiding device according to claim 1 , wherein each pile engaging device comprises a set of parallel cylinders.
5 . The heave tolerant pile guiding device according to claim 1 , wherein the position control circuit comprises:
a position controller;
a first position sensor associated with the first cylinder and linked to the position controller;
a second position sensor associated with the second cylinder and linked to the position controller;
a pump port connectable to a hydraulic pump;
a tank port connectable to a tank for hydraulic liquid; and
a position control valve assembly associated with the first and second cylinders, the pump port and the tank port, the position control valve assembly being linked to the position controller, the position control valve assembly governing hydraulic liquid flow to and from the first and second cylinders based on position control by the position sensors.
6 . The heave tolerant pile guiding device according to claim 1 , wherein the pile guiding device comprises multiple pairs of first and second pile engaging devices the pairs being arranged on the frame at angular offset positions relative to one another seen in a plan view of the pile guiding device, each pair having a respective hydraulic system with a position control circuit and a sphincter control circuit.
7 . A method for installation of a pile, the pile comprising a cylindrical section and above said cylindrical section a tapered section that narrows in upward direction, wherein use is made of the heave tolerant pile guiding device according to claim 1 for guiding the pile,
wherein, in response to the pile engaging members engaging on the tapered section, the hydraulic cylinders are operated in the sphincter mode, wherein the cylinders are hydraulically pressurized by the accumulator and thereby the pile engaging members are urged against the tapered section of the pile, and
wherein, during the downward motion of the pile guiding device relative to the tapered section of the pile, the cylinder bottom chambers expel hydraulic liquid via the first and second lines, respectively, the flow divider causing an equal flow of said expelled hydraulic fluid, some of said expelled hydraulic liquid being fed via the third line to the head chambers of the cylinders and some being received by the accumulator, and
wherein, during the upward motion of the pile guiding device relative to the tapered section of the pile, the accumulator feeds hydraulic liquid via the flow divider to the bottom chambers of the cylinders, the flow divider causing an equal flow of said feeds of hydraulic fluid, the head chambers expelling hydraulic liquid via said third line.
8 . A vessel equipped with the heave tolerant pile guiding device according to claim 1 for guiding a pile comprising the cylindrical section and above said cylindrical section the tapered section that narrows in upward direction, during installation thereof.