Isotope Brayton ground demonstration testing and flight qualification. Volume 1. Technical program

Guest Editorial: Situational awareness of integrated energy systems

International Journal of Computational Engineering ScienceVol. 05, No. 01, pp. 81-89 (2004) No AccessEVOLUTIONARY PROGRAMMING BASED ECONOMIC DISPATCH WITH LINE FLOW CONSTRAINTSP. SOMASUNDARAM, K. KUPPUSAMY, and R. P. KUMUDINI DEVIP. SOMASUNDARAMSchool of Electrical and Electronics Engineering, Anna University, Chennai, Tamil Nadu 600 025, India Search for more papers by this author , K. KUPPUSAMYSchool of Electrical and Electronics Engineering, Anna University, Chennai, Tamil Nadu 600 025, India Search for more papers by this author , and R. P. KUMUDINI DEVISchool of Electrical and Electronics Engineering, Anna University, Chennai, Tamil Nadu 600 025, India Search for more papers by this author https://doi.org/10.1142/S1465876304002277Cited by:1 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractThis paper presents an efficient, simple and new method for solving Economic Dispatch (ED) problem with line flow constraints through the application of Evolutionary Programming (EP). The controllable system quantities in the base-case state are optimized to minimize some defined objective function subject to the base-case operating constraints. A 10-bus system is taken for investigation. The ED results obtained using EP are compared with those obtained using quadratic programming. The investigations reveal that the proposed algorithm is relatively simple, reliable, efficient and suitable for on-line applications.Keywords:Power System OptimizationEconomic DispatchEvolutionary ProgrammingLine Flow Constraints References B. H. Chowdhury and S. Rahman, IEEE Transaction on power systems 5(4), 1248 (1990). Crossref, Google Scholar Nanda, L. Hari and M. L. Kothari, IEE Proceedings-C 141(1), 1 (1994). Google ScholarJ. Nandaet al., IEE Proceedings-C 139(1), 39 (1992). Google ScholarJ. Y. Fan and L. Zhang, IEEE Transactions on Power Systems 13(2), 320 (1998). Crossref, Google ScholarP. K. Hota, R. Chakrabarti and P. K. Chattopadhyay, Institute of Engineers (India) Journal-EL 81, 21 (2000). Google ScholarJ. Nanda and R. Badri Narayanan, Electrical Power and Energy Systems 24, 723 (2002). Crossref, Google Scholar D. B. Fogel , Evoluationary Computation: Toward a New Philosophy of Machine Intelligence ( IEEE Press , USA , 1995 ) . Google ScholarL. L. Lai and J. T. Ma, IEEE Transactions on Power Systems 12(1), 198 (1997). Crossref, Google ScholarH. T. Yang, P. C. Yang and C. L. Huang, IEEE Transactions on Power Systems 11(1), 112 (1996). Crossref, Google ScholarK. P. Wong and J. Yuryevich, IEEE Transactions on Power Systems 13(2), 301 (1998). Google ScholarT. Jayabarathi, G. Sadasivam and V. Ramachandran, Electric Power Systems Research 52, 261 (1999). Crossref, Google ScholarT. Jayabarathi and G. Sadasivam, European Transaction on Electrical Power 10(3), 167 (2000). Crossref, Google ScholarP. Attaviriyanupapet al., IEEE Transactions on Power Systems 17(2), 411 (2002). Crossref, Google Scholar FiguresReferencesRelatedDetailsCited By 1FDR PSO-based Transient Stability Constrained Optimal Power Flow Solution for Deregulated Power IndustryM. Anitha, S. Subramanian and R. Gnanadass28 Aug 2007 | Electric Power Components and Systems, Vol. 35, No. 11 Recommended Vol. 05, No. 01 Metrics History KeywordsPower System OptimizationEconomic DispatchEvolutionary ProgrammingLine Flow ConstraintsPDF download

A nuclear space power system that consists of a solid metal nuclear reactor core with heat pipes carrying energy to a cylindrical thermoelectric converter surrounding each of the heat pipes with a heat pipe radiator surrounding the thermoelectric converter is the most simple and reliable space power system. This means no single point of failure since each heat pipe and cylindrical converter is a separate power system and if one fails it will not affect the others. The heat pipe array in the solid core is designed so that if an isolated heat pipe or even two adjacent heat pipes fail, the remaining heat pipes will still transport the core heat without undue overheating of the uranium nitride fuel. The primary emphasis in this paper is on simplicity, reliability and fabricability of such a space nuclear power source. The core and heat pipes are made of Niobium 1% Zirconium alloy (Nb1Zr), with rhenium lined fuel tubes, bonded together by hot isostatic pressure, (HIPing) and with sodium as the heat pipe working fluid, can be operated up to 1250K. The cylindrical thermoelectric converter is made by depositing the constituents of the converter around a Nb1%Zr tube and encasing it in a Nb 1% Zr alloy tube and HIPing the structure to get final bonding and to produce residual compressive stresses in all brittle materials in the converter. A radiator heat pipe filled with potassium that operates at 850K is bonded to the outside of the cylindrical converter for cooling. The solid core heat pipe and cylindrical converter are mated by welding during the final assembly. A solid core reactor with 150 heat pipes with a 0.650‐inch (1.65 cm) ID and a 30‐inch (76.2 cm) length with an output of 8 Watts per square inch as demonstrated by the SP100 PD2 cell tests will produce about 80 KW of electrical power. An advanced solid core reactor made with molybdenum 47% rhenium alloy, with lithium heat pipes and the PD2 theoretical output of 11 watts per square inch or advanced higher temperature converter to operate at 1350K could produce a greater output of approximately 100KW.

Fraunhofer IMM develops CHP system with reformer/fuel cell

Space-based orbit determination problem using line-of-sight measurements appears in two equivalent cases: 1) to estimate the observer’s orbit when observing a known planetary body (navigation problem) and 2) to determine the orbit of an unknown observed body when the observer’s orbit is known (surveillance problem). These two problems are mathematically equivalent. Star trackers provide attitude autonomy to interplanetary missions while the estimation of position still relies on communications to Earth’s ground stations. This paper shows that, in interplanetary missions, autonomy for position estimation can be obtained just by observing visible planets using star trackers. In any space mission and, in particular interplanetary missions, autonomy plays a critical role for the success of the mission, especially if temporary or permanent failure occurs in the communication system. This study first solves the position and velocity (state) estimation problem as a single-point problem using the Pn space-based Initial Orbit Determination (IOD) algorithm 8 and then uses this estimation to initiate a filtered estimation of the state using Extended Kalman Filter (EKF). Space observations of line-of-sight directions constitute the measurements of two distinct problems: when estimating the orbit of an unknown observed body (space-based orbit determination problem) and when estimating the observer’s orbit when the observed body is known (navigation problem). There is a perfect duality between these two problems as they share the same mathematics meaning that any method capable of solving one problem can be used to solve the other. However, when the distances between observer and observed become large, as in interplanetary missions, the problem becomes more complicated. In fact, ∗Texas A&M University Affiliate. E-mail: reza.aero@gmail.com †Professor, 746C H.R. Bright Bldg, Aerospace Engineering, Texas A&M University, College Station, TX 77843-3141, AAS Fellow, AIAA Associate Fellow. IEEE Senior member. E-mail: mortari@tamu.edu

A Dynamic simulation Model (DynMo-CBC) is developed and demonstrated for a power system comprised of a gas cooled reactor and three independent CBC loops. The reactor core is divided into three sectors that are hydraulically independent, but thermally and neutronically coupled. Each reactor sector is directly coupled to a CBC loop with a Brayton Rotating Unit designated UNM-BRU-1 and NaK-78 secondary loop with water heat pipes radiator panels. The results presented are for the startup transient to steady-state operation of the space power system at a UNM-BRU-1 shaft speed of 45 krpm, turbine and compressor inlet temperatures of 1149 K and 400 K, and reactor thermal power of 471 kWth. At these conditions, the electrical power and thermal efficiency of the S^4-CBC power system are 130.8 kWe and 27.8%.

Although air transport is responsible for only about 2% of all anthropogenic CO2 emissions, the rapidly increasing volume of air traffic leads to a general concern about the environmental impact of aviation. Future aircraft generations have to face enhanced requirements concerning productivity, environmental compatibility and higher operational availability, thus effecting technical, operational and economical aspects of in-flight and on-ground power generation systems. Today’s development in aircraft architecture undergoes a trend to a “more electric aircraft” which is characterised by a higher proportion of electrical systems substituting hydraulically or pneumatically driven components, and, thus, increasing the amount of electrical power. Fuel cell systems in this context represent a promising solution regarding the enhancement of the energy efficiency for both cruise and ground operations. For several years the Institute of Technical Thermodynamics of the German Aerospace Center (Deutsches Zentrum fu¨r Luft- und Raumfahrt, DLR) in Stuttgart is engaged in the development of fuel cell systems for aircraft applications. The activities of DLR focus on: • Identification of fuel cell applications in aircraft in which the properties of fuel cell systems, namely high electric efficiency, low emissions and silent operation, are capitalized for the aircraft application. • Design and modeling of possible system designs. • Experimental investigations regarding specific aircraft relevant operating conditions. • Qualification of airworthy fuel cell systems. • Set up and full scale testing of fuel cell systems for application in research aircraft. In cooperation with Airbus several fuel cell applications within the aircraft for both ground and cruise operation could be identified. In consequence, fuel cell systems capable to support or even replace existing systems have been derived. In this context, the provision of inert gas for the jet fuel (kerosene) tank and electrical cabin power supply including water regeneration represent the most promising application fields. The contribution will present the state of development discussing the following points: • Modeling of different system architectures and evaluation of promising fuel cell technologies (PEFC vs. SOFC). • Experimental evaluation of fuel cell systems under relevant conditions (low-pressure, vibrations, reformate operation, etc.). • Fuel cell system demonstrator Hyfish (hydrogen powered model aircraft). • Fuel cell test in DLR’s research aircraft ATRA (A320) including the test of an emergency system based on hydrogen and oxygen with 20 kW of electrical power. The fuel cell system was integrated into an A320 aircraft and tested up to a flight altitude of 25 000 feet under several acceleration and inclination conditions.

Development and assessment of a thermochemical cycle and SOFC-based hydrogen energy system as a potential energy solution for the peak demand in a sustainable community

Using a combined energy cycle based on conventional and/ or clean energy sources can be a suitable option to dominate the limitations in the field of energy. Meanwhile, the select of the prime power source in such processes is a challengeable issue. The selection of the prime power source from renewable sources and in addition the use of system waste heat can lead to enhance power generation. In the present work, an energy system based on conventional energy sources and clean technology is introduced and investigated. The new integrated hybrid energy cycle is composed of Miller cycle engine (MC), alkaline fuel cell (AFC), alkaline electrolyzer, Organic Rankine cycle (ORC) system and Stirling engine. MC and AFC are used as the main power sources of the cycle. On the other hand, ORC and Stirling engine for generating more electricity from the waste heat of the cycle are applied. The electrolyzer embedded in the cycle receives its electricity from the MC and provides the required inputs of the AFC. Although many studies had been done on the integration of various power generation sources with different energy cycles, attempts had not been done to establish a study on the hybrid of MC, AFC, alkaline electrolyzer, Stirling engine and ORC to produce additional electricity. Results revealed that the introduced energy system generates 3.75 kW of electric power. The portion of MC, fuel cell, ORC, and Stirling engine in electric power production is 71.2, 10.8, 9.5 and 8.5%, respectively. However, the alkaline electrolyzer consumes 2.06 kW of power and generates 48.2 g/h of H2 fuel. It was also found that the cycle exergy destruction is 3.34 kW. In addition, the use of MC and AFC heat dissipation heat can enhance power generation.

Performance characterization of gas engine generator integrated with a liquid desiccant dehumidification system

Application of advanced exergy analysis for optimizing the design of carbon dioxide pressurization system

On-board H 2 generation by catalytic dehydrogenation of hydrocarbon mixtures or fuels

Carnegie Mellon University’s departments of Architecture and Mechanical Engineering have designed and installed a biodiesel fueled engine-generator with heat recovery equipment to supply electric and thermal power to an office building on campus, the Intelligent Workplace (IW). The installation was completed in early September 2007, and was commissioned through April of 2008 with standard off-road low sulfur Diesel (LSD) fuel. Additional baseline testing was conducted with LSD until October 2008, when the transition was made to a 100% soybean oil based biodiesel. The turbocharged diesel engine-generator set is operated in parallel with the local electric utility and the campus steam grid. The system is capable of generating 25 kW of electric power while providing 18 kW of thermal power in the form of steam from an exhaust gas boiler and 19 kW in the form of heated water from the engine coolant. The steam is delivered to a double-effect Lithium-Bromide (Li-Br) absorption chiller, which supplies chilled water to the IW for space cooling in the summer or hot water for space heating in the winter. Furthermore, the steam can be delivered to the campus steam grid during the fall and spring when neither heating nor cooling is required in the IW. The thermal energy recovered from the coolant provides hot water for space heating in the winter, and for regenerating a solid desiccant dehumidification ventilation system in summer. All relevant temperatures, pressures, and flows for these systems are monitored via a building automation system. Pressure versus time versus crank angle measurements are recorded in each cylinder of the engine. Emissions of nitric oxide (NO), nitrogen dioxide (NO2), Particulate Matter (PM), carbon monoxide (CO) and carbon dioxide (CO2) are also monitored. The performance testing thus far indicates that biodiesel fuel performs just as well as Diesel fuel in the CHP system, providing similar amounts of electrical and thermal energy at the similar temperatures and flows at a similar overall efficiency. As expected, the engine consumes more biodiesel fuel due to the lower energy density of biodiesel fuel compared to LSD. Upon completion of the system performance testing with different types of biodiesel fuel, the operation of the engine generator with its heat recovery components will be integrated with the other HVAC components of the IW including a parabolic trough solar thermal driven Li-Br absorption chiller, a solid desiccant dehumidification ventilation system, and multiple types of fan coils and radiant heating and cooling devices. This integrated energy supply system is expected to reduce the IW’s primary energy consumption by half in addition to the 75% site energy savings already realized by architectural features as compared to the average US office space.

The Dynamic Isotope Power System (DIPS) can supply three to four times more electrical power than Radioisotope Thermoelectric Generators (RTGs) for the same amount of Pu‐238 fuel. The available electrical power can be used to drive propellant‐efficient electric thrusters, which would enable and/or significantly enhance the capabilities of interplanetary missions. Because of this, the DIPS program has been reviewing the application of DIPS technology to the interplanetary missions in the 500 We to 1.0 kWe power range. Such a DIPS program would focus on completing an Integrated System Test (IST) of the DIPS in a simulated space environment. The DIPS IST would fully demonstrate DIPS integrated operation, long‐term containment boundary integrity, and, most importantly, DIPS flight readiness. To reduce cost, schedule, and risk of the DIPS development, the design would use the DOE‐developed Brayton Isotope Power System (BIPS) turboalternator compressor (TAC), which is currently being refurbished for use in the NASA‐LeRC Solar Dynamic Ground Test Demonstration (SD GTD) Program. The DIPS IST, which would follow the SD GTD testing, would make use of common elements with the SD GTD wherever practical to reduce the IST cost and schedule. The components demonstrated in the IST would be flight prototypical except that full flight qualification would not be performed. For future interplanetary applications, the DIPS system would employ the identical TAC design demonstrated in the IST for all applications. Power level scalability would be achieved by scaling other loop components in a straightforward manner without technology development or requalification. This will significantly reduce costs while providing only a small scalability performance penalty.

Due to the increasing penetration of gas-fired units and power to gas facilities, the electrical power system and natural gas system are more and more bi-directionally coupled. To tackle the challenges on the optimal scheduling operation of an integrated gas and power systems (IGPS), this article focuses on developing a novel approach to build a continuous spatial-temporal optimal operation schedule model. In the light of different time constants of the electrical power and natural gas systems, the continuous spatial-temporal optimal operation schedule model of IGPS is formulated in function space. Additionally, Bernstein polynomials are used to reformulate the continuous spatial-temporal optimization problem of IGPS to mixed-integer linear programming. In the study cases, the simulation results of a simple integrated system and a combined IEEE 39-bus power system and Belgian natural gas network demonstrate the accuracy and effectiveness of the proposed model.