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24-853: The title "power engineer" is used differently between the United States and Canada. Stationary engineers are responsible for the safe operation and maintenance of a wide range of equipment including boilers, steam turbines, gas turbines, gas compressors, generators, motors, air conditioning systems, heat exchangers, heat recovery steam generators (HRSGs) that may be directly fired (duct burners) or indirectly fired (gas turbine exhaust heat collectors), hot water generators, and refrigeration machinery in addition to its associated auxiliary equipment ( air compressors , natural gas compressors , electrical switchgear , pumps , etc.). Stationary engineers are trained in many areas, including mechanical, thermal, chemical, electrical, metallurgy, instrumentation, and

48-626: A Bachelor of Science degree in mechanical engineering . Holders of the Stationary Engineer's License primarily work in large power generation facilities, such as cogeneration power plants, peaking units, and large central heating and refrigeration plants (CHRPs). For the State of California, Stationary Engineers are the State of California Military Department's sole source of Airfield Lighting and Repair. Heat recovery steam generator A heat recovery steam generator ( HRSG )

72-523: A water-cooled furnace, which allows for higher supplemental firing and better overall efficiency. Some HRSGs include supplemental, or duct firing. These additional burners provide additional energy to the HRSG, which produces more steam and hence increases the output of the steam turbine . Generally, duct firing provides electrical output at lower capital cost. It is therefore often utilized for peaking operations. HRSGs can also have diverter valves to regulate

96-498: A wide range of safety skills. They typically work in factories , office buildings, hospitals , warehouses , power generation plants, industrial facilities, and residential and commercial buildings. The use of the title Stationary Engineer predates other engineering designations and is not to be confused with Professional Engineer , a title typically given to design engineers in their given field. The job of today's engineer has been greatly changed by computers and automation as well as

120-422: Is an energy recovery heat exchanger that recovers heat from a hot gas stream, such as a combustion turbine or other waste gas stream. It produces steam that can be used in a process ( cogeneration ) or used to drive a steam turbine ( combined cycle ). HRSGs consist of four major components: the economizer , evaporator , superheater and water preheater . The different components are put together to meet

144-467: Is currently thrown away by industry. " A 2007 Department of Energy study found the potential for 135,000 megawatts of combined heat and power (which uses energy recovery) in the U.S., and a Lawrence Berkley National Laboratory study identified about 64,000 megawatts that could be obtained from industrial waste energy, not counting CHP. These studies suggest that about 200,000 megawatts, or 20%, of total power capacity could come from energy recycling in

168-448: Is generated at single pressure level whereas multi pressure HRSGs employ two (double pressure) or three (triple pressure) steam drums. As such triple pressure HRSGs consist of three sections: an LP (low pressure) section, a reheat/IP (intermediate pressure) section, and an HP (high pressure) section. Each section has a steam drum and an evaporator section where water is converted to steam. This steam then passes through superheaters to raise

192-453: Is ideal for cycling and base load operation. With proper material selection, an OTSG can be run dry, meaning the hot exhaust gases can pass over the tubes with no water flowing inside the tubes. This eliminates the need for a bypass stack and exhaust gas diverter system which is required to operate a combustion turbine with a drum-type HRSG out of service. Energy recovery Energy recovery includes any technique or method of minimizing

216-425: Is necessary to make energy recovery practicable. One example is waste heat from air conditioning machinery stored in a buffer tank to aid in night time heating . A common application of this principle is in systems which have an exhaust stream or waste stream which is transferred from the system to its surroundings. Some of the energy in that flow of material (often gaseous or liquid ) may be transferred to

240-475: Is not common. In the United States, stationary engineers must be licensed in several cities and states . The New York City Department of Buildings requires a Stationary Engineer's License to practice in the City of New York ; to obtain the license one must pass a written and practical exam and have at least five years' experience working directly under a licensed stationary engineer, or one year if in possession of

264-431: Is the once-through steam generator. In this design, the inlet feedwater follows a continuous path without segmented sections for economizers, evaporators, and superheaters. This provides a high degree of flexibility as the sections are allowed to grow or contract based on the heat load being received from the gas turbine. The absence of drums allows for quick changes in steam production and fewer variables to control, and

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288-497: The HVAC systems, or process systems. Energy consumption is a key part of most human activities. This consumption involves converting one energy system to another , for example: The conversion of mechanical energy to electrical energy, which can then power computers, light, motors etc. The input energy propels the work and is mostly converted to heat or follows the product in the process as output energy. Energy recovery systems harvest

312-512: The Industrial Revolution with the development of steam-powered pumps by Thomas Savery and Thomas Newcomen which were used to draw water from mines, and the industrial steam engines perfected by James Watt . Railroad engineers operated early steam locomotives and continue to operate trains today, as well as marine engineers, who operated the boilers on steamships . The certification and classification of stationary engineers

336-448: The make-up or input material flow. This input mass flow often comes from the system's surroundings, which, being at ambient conditions, are at a lower temperature than the waste stream . This temperature differential allows heat transfer and thus energy transfer, or in this case, recovery. Thermal energy is often recovered from liquid or gaseous waste streams to fresh make-up air and water intakes in buildings , such as for

360-670: The Standardization of Power Engineers Examinations Committee (SOPEEC) who receives recommendations by the Interprovincial Power Engineering Curriculum Committee (IPECC). In the United States power engineers are governed solely by their individual states, or by their specific municipalities. Several States, such as Maine have opted to align with Canada's guidelines regarding power engineering education, however, this

384-426: The exhaust gases. There is a large potential for energy recovery in compact systems like large industries and utilities. Together with energy conservation , it should be possible to dramatically reduce world energy consumption . The effect of this will then be: In 2008 Tom Casten , chairman of Recycled Energy Development , said that " We think we could make about 19 to 20 percent of U.S. electricity with heat that

408-441: The inlet flow into the HRSG. This allows the gas turbine to continue to operate when there is no steam demand or if the HRSG needs to be taken offline. Emissions controls may also be located in the HRSG. Some may contain a selective catalytic reduction system to reduce nitrogen oxides (a large contributor to the formation of smog and acid rain) or a catalyst to remove carbon monoxide . The inclusion of an SCR dramatically affects

432-479: The input of energy to an overall system by the exchange of energy from one sub-system of the overall system with another. The energy can be in any form in either subsystem, but most energy recovery systems exchange thermal energy in either sensible or latent form. In some circumstances the use of an enabling technology, either daily thermal energy storage or seasonal thermal energy storage (STES, which allows heat or cold storage between opposing seasons),

456-528: The layout of the HRSG. NOx catalyst performs best in temperatures between 650 and 750 °F (343–399 °C). This usually means that the evaporator section of the HRSG will have to be split and the SCR placed in between the two sections. Some low-temperature NOx catalysts have recently come to market that allow for the SCR to be placed between the evaporator and economizer sections (350–500 °F [177–260 °C]). A specialized type of HRSG without boiler drums

480-640: The operating requirements of the unit. See the attached illustration of a Modular HRSG General Arrangement. Modular HRSGs can be categorized by a number of ways such as direction of exhaust gases flow or number of pressure levels. Based on the flow of exhaust gases, HRSGs are categorized into vertical and horizontal types. In horizontal type HRSGs, exhaust gas flows horizontally over vertical tubes whereas in vertical type HRSGs, exhaust gas flow vertically over horizontal tubes. Based on pressure levels, HRSGs can be categorized into single pressure and multi pressure. Single pressure HRSGs have only one steam drum and steam

504-422: The output power and provide this as input power to the same or another process. An energy recovery system will close this energy cycle to prevent the input power from being released back to nature and rather be used in other forms of desired work. Electric Turbo Compounding (ETC) is a technology solution to the challenge of improving the fuel efficiency of gas and diesel engines by recovering waste energy from

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528-430: The replacement of steam engines on ships and trains. Workers have adapted to the challenges of the changing job market. Today, stationary engineers are required to be significantly more involved with the technical aspect of the job, as many plants and buildings are updated with increasingly more automated systems of control valves and distributed control systems . The profession of stationary engineering emerged during

552-508: The temperature beyond the saturation point. The steam and water pressure parts of an HRSG are subjected to a wide range of degradation mechanisms, for example creep , thermal fatigue , creep-fatigue, mechanical fatigue, Flow Accelerated Corrosion (FAC), corrosion and corrosion fatigue, amongst others. Packaged HRSGs are designed to be shipped as a fully assembled unit from the factory. They can be used in waste heat or turbine (usually under 20 MW) applications. The packaged HRSG can have

576-593: Was developed in order to reduce incidents of boiler explosions in the late 19th century. Notable individuals who worked as stationary engineers include George Stephenson , William Faulkner, and Henry Ford . In Canada, power engineers are regulated by their respective jurisdictions. Each province has a safety authority that is granted power through "enabling acts" and overseen by the Canadian Standards Association. Examinations and licensing in all 10 provinces and three territories are regulated by

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