Oceanic Thermal Energy Conversions EM-2017 Mech Dept

Background Information OTEC system is based on the Rankine Cycle Uses the vertical temperature gradient in the ocean as a heat sink/source Mainly used in equatorial waters where temperature gradient is greatest

Closed Rankine Cycle Overview 1-2 Power in to pressurize liquid to higher pressure 2-3 Heat addition to evaporate ammonia 3-4 Work produced from expansion through turbine 4-1 Heat extraction to condense the ammonia before pump

Closed Rankine Cycle Calculations

Pros of OTEC Extremely benign impact on environment No dependency on oil Minimal maintenance costs compared to conventional power production plants Open cycle OTEC systems can produce desalinated water which is very important in third-world countries

Cons of OTEC Low thermal efficiency due to small temperature gradient between heat sink and source OTEC technology is only ideally suitable in equatorial waters Only moderate power outputs are available Currently this technology is not as monetarily feasible as conventional power production plants The manufacturing and installation of the extremely long cold water pipes is extremely time consuming and costly.

Problem Statement To create and design an operating Oceanic Thermal Energy Conversion model that employs a closed Rankine Cycle that utilizes ammonia as the working fluid to illustrate the viability of OTEC power production.

Specifications Produce 100 Watts of power Be smaller than 8 ft. wide, 6 ft. tall, and 2 ft. deep. Final product must be easily portable. OTEC model must be aesthetically pleasing and allow viewers to easily understand and view the inner-workings of the Rankine Cycle utilized by OTEC systems. Must start and stop operation using simple mechanical or electrical devices Must not endanger the operator or anyone viewing the OTEC presentation

Heat Pump Conversion One possible design idea is to convert a heat pump into a power producing Rankine Cycle Many moderately sized Geothermal energy cycles use large commercially available AC units. Objective is to make the compressor function as a turbine/generator Add an auxiliary pump to circulate and pressurize the working fluid throughout the cycle Very little modification is necessary to convert heat pumps and AC units into power producing units