Energy Conversion (EC) Systems
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Introduction
��ࡱ�>�� ^`����]�������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������[email protected] ��0�lbjbj�2�2 (��X�Xb�������������������8� �\�ovZZZZZZZZ�������$�R7��ZZZZZ��ZZ)���Z�Z�Z��Z�������ZN P�È��ZX��?0o�� � � �������� �� ZZ�ZZZZZ�Energy Conversion (EC) Systems Integrated Gasification Combined Cycle Fuel Cell Magnetohydrodynamics The first-generation version of most of these systems is either commercially available or under demonstration today. Descriptions Pressurized Fluidized-Bed Combustion This coal fired combustion system reduces sulfur and nitrogen pollutants inside the boiler, eliminating the need for expensive add-on equipment. The hot, high-pressure gases produced by pressurized fluidized-bed combustors can power a "combined cycle" arrangement of gas and steam turbines. First-generation systems, with 40 to 42 percent efficiencies, are being commercially demonstrated. More advanced concepts are expected to boost efficiencies between 45 percent and 50 percent. These advanced systems will be capable of reducing sulfur dioxide by 95 percent and nitrogen oxides by 85 percent. Indirectly Fired Cycle The combustion gases created by burning coal in this high performance power system are prevented from contacting a gas turbine. Instead, they transfer heat to an impurity free gas that powers the turbine. Currently, in the conceptual design phase, indirectly fired cycle systems could offer a coal-based technology with efficiencies approaching 50 percent, with sulfur dioxide, nitrogen oxides, and particulates reduced to one fourth of the New Source Performance Standards. Advanced Gas Turbine Like fuel cells, advanced gas turbine systems are being developed initially for natural gas, with a future option to adapt to coal-derived gas. Advanced turbine systems being developed for the 21 st century will be capable of breaking through the temperature barrier that limits the efficiency of today's systems, while significantly reducing nitrogen oxides emissions. Magnetohydrodynamics This coal-based power option operates at ultra-high temperatures, producing a plasma which, when channeled through a magnetic field, can generate electrical current. Combined with a steam turbine-generator, magnetohydrodynamics systems are projected to be capable of efficiencies exceeding 50 percent with very low emissions. Benefits Advanced energy conversion technologies being developed by private industry and the U.S. ...read more.
Middle
Thus, it can be said that entropy is a measure of the 'unavailability' of internal energy. Power Cycle Components/Processes Most power and propulsion devices can be considered to comprise a number of simple processes. The most common are: expansion, compression, heat exchange, mixing, separation of constituents of mixtures, and chemical reactions including combustion of fuels. Expansion In power plants expansion generally occurs at temperatures above the environmental temperature. Except for throttling, the purpose of an expansion process is to deliver power at the expense of a reduction in the exergy of the stream of the working fluid. Most common expanders are rotodynamic and are usually treated as adiabatic. Expansion can occur as a single or a multi-stage expansion process. Compression In applications such as power plants, compressed air installations, gas pipelines a liquefaction plants compression usually starts at approximately environmental temperature. In refrigeration plants and heat pumps, compression processes start at temperatures lower than To, but usually end above it. Heat Transfer Heat transfer processes may be usefully divided into two groups. Group 1: In this group of heat transfer processes the thermal component of exergy of one stream increases at the expense of a reduction in the thermal component of exergy of another stream. Thus in this case a heat exchanger transfers thermal exergy between two streams through conductive, convective or radiant heat transfer. Since there is a useful output expressible in terms of exergy, a rational efficiency can be formulated. Group 2: This group of heat transfer processes is characterized by transfer of thermal energy to or from the environment. In some heat transfer processes such as those found in cooling towers and refrigerator condensers, the stream, at T > To, transfers heat to the environment. In heat pump evaporators, however, the stream is at a temperature lower than To, and heat transfer is from the environment. In either case the exergy of the stream decreases as a result of the heat transfer, and since the exergy of the environment can never increase, heat transfer processes in this group lead only to dissipation of exergy. ...read more.
Conclusion
Sulfur: An element present in varying quantities in coal; contributes to environmental degradation when coal is burned. The sulfur content in coal is low if 1% or less, medium if between 1% and 3%, and high if over 3%. Total Resources: Coal deposits both known and undiscovered, estimated at 4 trillion tons in the U.S. and as much as 14 trillion tons worldwide. Turbine: A device with rotating vanes for generating rotary mechanical power from the kinetic energy in a stream of fluid or gas. Underground Gasification: See In-Situ Gasification. This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ jj�j�j�j�jokpk�k�kSlTl�l�l�l�l������������h�h�OJQJh�h�CJOJQJ%h�h�OJQJfHq� ����)h�h�CJOJQJfHq� ����h�h84 h84h� !HITUlm���� q r s t � � i j k l � � �� �����������������������������gd84j�l�� UV`a����PQQR����hi��'(xy�������������������������������gd84��,-01��ST" "M$N$�%�%&&�&�& ' '�'�':+;+�+�+�+�����������������������������gd84�+�+'-(-////0000006070�0�0�0�0�0�0#1$1:1;1�1�1�1�1�����������������������������gd84�1�2�2�2�2 3 3�5�5�5�5�7�7�7�7�8�8�8�8�:�:�:�:�;�;�;�;<<�=�����������������������������gd84�=�=�A�A�A�A,B-B`BaBqBrB�B�B�B�B�B�B�D�D�D�D�F�F�F�FNIOI�J�J�����������������������������gd84�J�J�J`KaKLLFLGL�L�L^M_M,N-N�N�N{O|O�O�OP POQPQ�Q�Q�Q�Q�R�����������������������������gd84�R�RMSNS�S�S�T�TUU�U�UV�V�V�V0W1W�W�W�X�XYY�Y�YZZ�Z�Z�����������������������������gd84�Z�[�[#\$\]]�]�]P^Q^+_,_~__A`B`-a.a�a�aKbLb�b�b3c4cdde�����������������������������gd84eeJeKe f f�f�fg g�g�g�h�hbici�i�ijj�j�j�j�j�j�jkk���������������������������$a$gd�gd84kpkqkrksk�k�k�k�kTlUlVlWl�l�l�l�l�l�l������������������gd84$a$gd�$a$gd�&1�h:p84��/ ��=!�'"�'#��$��%��[email protected]�D NormalCJ_H aJmH nHsH [email protected]�D Default Paragraph FontRi�R Table Normal�4� l4�a� (k�(No [email protected]�D 84 Plain TextCJOJQJ^[email protected] �Header ���!4 @4 �Footer ���!`�o"` �watermark header$a$CJOJQJfHq� ����N�o2N �watermark footer$a$ CJOJQJ�d�����r�V�:���l7 �+�1�=�J�R�Zek�l8:;<=>[email protected]�l9bb�b�b�bcqcsc�c�cUdWd�d�d�d��alex��84�@b,�q�[email protected]��Unknown������������G��z ��Times New Roman5V��Symbol3&� �z ��Arial7&� � �VerdanaG5�� �����h�MS Mincho-�3� fg?5� �z ��Courier New"1���h��f��f��f��S�$��S�$$�������4�b�b3�� H�?������������������84��Energy Conversion (EC) Systems TCoursework.Info Coursework - http://www.coursework.info/ - Redistribution ProhibitedTCoursework.Info Coursework - http://www.coursework.info/ - Redistribution Prohibitedalexalex�� ��Oh��+'��0|���(8��� , 8 D P\dlt� Energy Conversion (EC) Systems UCoursework.Info Coursework - http://www.coursework.info/ - Redistribution ProhibitedualexewoUCoursework.Info Coursework - http://www.coursework.info/ - Redistribution Prohibitedu>Downloaded from Coursework.Info - http://www.coursework.info/is Normal.dotfalexl.d2exMicrosoft Word [email protected]@�r È�@�r È�@�r È���S�� ��Õ.��+,��D��Õ.��+,���<���H����� ���� � �UCoursework.Info Coursework - http://www.coursework.info/ - Redistribution Prohibiteds UCoursework.Info Coursework - http://www.coursework.info/ - Redistribution Prohibiteds UCoursework.Info Coursework - http://www.coursework.info/ - Redistribution Prohibiteds 5c$��bA Energy Conversion (EC) Systems [email protected]���+K_PID_LINKBASE CopyrightDownloaded FromCan RedistributeOwner�A4http://www.coursework.comcoursework.comehttp://www.coursework.com No, do not redistributecoursework.com/ !"#$%&'()*+,-./0123456789:;<=>[email protected]����FGHIJKL����NOPQRST����VWXYZ[\��������_������������������������������������������������������������������������������������������������������������������������������������Root Entry�������� �F�!�È�a�1Table��������EWordDocument��������(�SummaryInformation(����MDocumentSummaryInformation8������������UCompObj������������j������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������ ���� �FMicrosoft Word Document MSWordDocWord.Document.8�9�q ...read more.
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