Self-energy storage device and method applied to constant mooring tension

A self-energy storage device applied to constant mooring tension, comprising:

• a hydraulic cylinder, wherein a piston rod of the hydraulic cylinder is connected to one end of a cable;
• and
• an energy storage module, wherein the energy storage module comprises a first accumulator and a second accumulator, a volume of the second accumulator is greater than a volume of the first accumulator, and a maximum pressure of the first accumulator is set greater than a maximum pressure of the second accumulator;
• wherein the first accumulator and the second accumulator are respectively connected to an oil chamber of the hydraulic cylinder via a hydraulic pipeline, and the first accumulator and the second accumulator are connected to each other via the hydraulic pipeline;
• the first accumulator and the second accumulator are configured to adjust an amount of hydraulic oil in the hydraulic cylinder for adjusting a pressure in the hydraulic cylinder, so as to maintain a tension in the cable constant near a preset value during operation;
• and
• the energy storage module further comprises:
• a first check valve disposed between the first accumulator and the hydraulic cylinder and configured to control whether the hydraulic oil in the oil chamber is transmitted to the first accumulator;
• a second check valve disposed between the second accumulator and the hydraulic cylinder and configured to control whether the hydraulic oil in the second accumulator is transmitted to the oil chamber;
• a first relief valve disposed on the hydraulic pipeline between the first accumulator and the second accumulator, and configured to control the maximum pressure of the first accumulator;
• a second relief valve connected to the second accumulator via the hydraulic pipeline and configured to control the maximum pressure of the second accumulator;
• and
• an oil tank connected to the second relief valve for storing the hydraulic oil from the second accumulator.