Liquid air/nitrogen energy storage and power generation are studied. Integration of liquefaction, energy storage and power recovery is investigated. Effect of turbine and compressor efficiencies on system performance predicted. The round trip efficiency of liquid air system reached 84.15%.
The operating pressure is 0.1 MPa for both inside nitrogen storage vessel and outside vacuum jacketed vessel. The present work explores the proper design guidelines for the design of storage vessel which can which can withstand the differential pressure with minimum heat loss using ASME codes and standards.
The drawback of these systems is low turnaround efficiencies due to liquefaction processes being highly energy intensive. In this paper, the scopes of improving the turnaround efficiency of such a plant based on liquid Nitrogen were identified and some of them were addressed.
The heat transfer coefficients varies amount gas conduction heat load is coming to the liquid nitrogen container. container carrying LN2 from atmospheric conditions. The vacuum space between the nitrogen storage vessel and vacuum jacketed vessel, reduce the heat loss due to conduction and convection.
Scheme 1 liquid nitrogen energy storage plant layout. At the peak times, the stored LN2 is used to drive the recovery cycle where LN2 is pumped to a heat exchanger (HX4) to extract its coldness which stores in cold storage system to reuse in liquefaction plant mode while LN2 evaporates and superheats.
The liquid nitrogen storage vessel has been designed as per ASME Boiler and Pressure Vessel Code. ASME section II used for material selection, section V used for nondestructive testing like weld defect detection, section VIII division 1 used for design of components and section IX used for welding and brazing qualification.