Energy conversion thermal

Fuel Cell Catalysts. Euel cells (qv) are electrochemical devices that convert the chemical energy of a fuel direcdy into electrical and thermal energy. The fuel cell, an environmentally clean method of power generation (qv), is more efficient than most other energy conversion systems. The main by-product is pure water. 

W. H. Avery, R. W. Blevins, G. L. Dugyer, and E. J. Francis, Executive Summary—Maritime and Construction Aspects of Ocean Thermal Energy Conversion (OTEC) Plant Ships, Apphed Physics Laboratory, The Johns Hopkins University, Baltimore, Md., Apr. 1976. 

Fig. 18. Flow schematic of an open-cycle ocean—thermal energy conversion (OTEC) and desalination plant (77), where (—) represents liquids (-),...

Peter J Loftus, D PhlL, Arihur D. Little, Inc. Member, American Society of Mechanical Engineers. (Heat Generation, Thermal Energy Conversion and Utilization, Heat Recovery)... 

Cogeneration is an energy conversion process wherein heat from a fuel is simultaneously converted to useful thermal energy (e.g., process steam) and electric energy. The need for either form can be the primary incentive for cogeneration, but there must be opportunity for economic captive use or sale of the other. In a chemical plant the need for process and other heating steam is hkely to be the primaiy in a pubhc utility plant, electricity is the usual primary produc t. 

A. Chambeiiand, S. Levesque Hydroeleetrieity, an option to reduee greenhouse gas emissions from thermal power plants . Energy Conversion and Management 37(6-8) 885-890 1996. 

One form of solar heat does offer interesting possibilities and is refeiTcd to as OTEC (Ocean-Thermal Energy Conversion). The OTEC power plant principle uses the solar heat of ocean surface water to vaporize ammonia as a working fluid in a Rankine cycle. After the fluid is expanded in the turbine, it is condensed by the 22°C colder... 

Ocean thermal energy conversion (OTEC) power plants generate electricity by exploiting the difference in temperature between warm water at the ocean surface and colder waters found at ocean depths. To effectively capture this solar energy, a temperature difference of 35°F or more between surface waters and water at depths of up to 3,000 feet is required. This situation can be found in most of the tropical and subtropical oceans around the world that are in latitudes between 20 degrees north and 20 degrees south. 

Electrochemical power sources differ from others, such as thermal power plants, by the fact that the energy conversion occurs without any intermediate steps for example, in the case of thermal power plants fuel is first converted in thermal energy, and finally electric power is produced using generators. In the case of electrochemical power sources this otherwise multistep process is achieved directly in only one step. As a consequence, electrochemical systems show some advantages, such as energy efficiency. 

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