Coupling of an offshore wind-driven deep sea water pump to an air cycle machine for large-scale cooling applications

Abstract

A system for using offshore wind energy to directly provide large-scale cooling through the exploitation of cold deep seawater below thermocline formations is proposed. The concept is based on an offshore wind-driven hydraulic pump supplying high pressure deep seawater to a land based plant. This pressurised seawater is used to power a hydraulic turbine which drives an inverse Brayton air cycle machine,

and is then diverted to a heat exchanger to cool the pressurised air prior to flowing back to the sea. A mathematical model for steady-state performance analysis of the proposed system under specified ambient conditions is presented. It was found that the system coefficient of performance was highest at low wind speeds and improved with increasing ambient temperature and humidity. This makes the system ideal for hot and humid climates. The availability of a sufficiently cold deep seawater resource was also found to be crucial for the viability of the system.