Which device is used in storing the energy of a fluid in the form of pressure energy?

Option 2 : Hydraulic accumulator

Explanation:

Hydraulic accumulator:

• Hydraulic accumulator is a device used for storing the energy of a liquid in the form of pressure energy, which may be supplied for any intermittent or sudden requirement.
• In the case of a hydraulic lift or a hydraulic crane, a large amount of energy is required when the lift or crane is moving upward.
• This energy is supplied from a hydraulic accumulator.
• When the lift is moving in the downward direction, no large external energy is required and at that time, the energy from the pump is stored in the hydraulic accumulator.
• The below figure shows a hydraulic accumulator.

• It consists of fixed vertical cylinder containing a sliding ram.
• A heavy weight is placed on the ram. 
• The inlet of the cylinder is connected to the pump, which continuously supplies water under pressure to the cylinder.
• The outlet of the cylinder is connected to the machine.