WorldWideScience

Sample records for thermal power module

  1. A Lumped Thermal Model Including Thermal Coupling and Thermal Boundary Conditions for High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2018-01-01

    Detailed thermal dynamics of high power IGBT modules are important information for the reliability analysis and thermal design of power electronic systems. However, the existing thermal models have their limits to correctly predict these complicated thermal behavior in the IGBTs: The typically used...... thermal model based on one-dimensional RC lumps have limits to provide temperature distributions inside the device, moreover some variable factors in the real-field applications like the cooling and heating conditions of the converter cannot be adapted. On the other hand, the more advanced three......-dimensional thermal models based on Finite Element Method (FEM) need massive computations, which make the long-term thermal dynamics difficult to calculate. In this paper, a new lumped three-dimensional thermal model is proposed, which can be easily characterized from FEM simulations and can acquire the critical...

  2. General 3D Lumped Thermal Model with Various Boundary Conditions for High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2016-01-01

    Accurate thermal dynamics modeling of high power Insulated Gate Bipolar Transistor (IGBT) modules is important information for the reliability analysis and thermal design of power electronic systems. However, the existing thermal models have their limits to correctly predict these complicated...... thermal behaviors in the IGBTs. In this paper, a new three-dimensional (3D) lumped thermal model is proposed, which can easily be characterized from Finite Element Methods (FEM) based simulation and acquire the thermal distribution in critical points. Meanwhile the boundary conditions including...... the cooling system and power losses are modeled in the 3D thermal model, which can be adapted to different real field applications of power electronic converters. The accuracy of the proposed thermal model is verified by experimental results....

  3. Thermal Simulation of Switching Pulses in an Insulated Gate Bipolar Transistor (IGBT) Power Module

    Science.gov (United States)

    2015-02-01

    executed with SolidWorks Flow Simulation , a computational fluid-dynamics code. The graph in Fig. 2 shows the timing and amplitudes of power pulses...defined a convective flow of air perpendicular to the bottom surface of the mounting plate, with a velocity of 10 ft/s. The thermal simulations were...Thermal Simulation of Switching Pulses in an Insulated Gate Bipolar Transistor (IGBT) Power Module by Gregory K Ovrebo ARL-TR-7210

  4. Miniaturization, Packaging, and Thermal Analysis of Power Electronics Modules

    OpenAIRE

    Lostetter, Alexander B.

    1998-01-01

    High power circuits, those involving high levels of voltages and currents to produce several kilowatts of power, would possess an optimized efficiency when driven at high frequencies (on the order of MHz). Such an approach would greatly reduce the size of capacitive and magnetic components, and thus ultimately reduce the cost of the power electronic circuits. The problem with this strategy in conventional packaging, however, is that at high frequencies, interconnects between the power devic...

  5. Engineering aspects of a thermal control subsystem for the 25 kW power module

    Science.gov (United States)

    Schroeder, P. E.

    1979-01-01

    The paper presents the key trade study results, analysis results, and the recommended thermal control approach for the 25 kW power module defined by NASA. Power conversion inefficiencies and component heat dissipation results in a minimum heat rejection requirement of 9 kW to maintain the power module equipment at desired temperature levels. Additionally, some cooling capacity should be provided for user payloads in the sortie and free-flying modes. The baseline thermal control subsystem includes a dual-loop-pumped Freon-21 coolant with the heat rejected from deployable existing orbiter radiators. Thermal analysis included an assessment of spacecraft orientations, radiator shapes and locations, and comparison of hybrid heat pipe and all liquid panels.

  6. Analyzing Thermal Module Developments and Trends in High-Power LED

    Directory of Open Access Journals (Sweden)

    Jung-Chang Wang

    2014-01-01

    Full Text Available The solid-state light emitting diode (SSLED has been verified as consumer-electronic products and attracts attention to indoor and outdoor lighting lamp, which has a great benefit in saving energy and environmental protection. However, LED junction temperature will influence the luminous efficiency, spectral color, life cycle, and stability. This study utilizes thermal performance experiments with the illumination-analysis method and window program (vapour chamber thermal module, VCTM V1.0 to investigate and analyze the high-power LED (Hi-LED lighting thermal module, in order to achieve the best solution of the fin parameters under the natural convection. The computing core of the VCTM program employs the theoretical thermal resistance analytical approach with iterative convergence stated in this study to obtain a numerical solution. Results showed that the best geometry of thermal module is 4.4 mm fin thickness, 9.4 mm fin pitch, and 37 mm fin height with the LED junction temperature of 58.8°C. And the experimental thermal resistances are in good agreement with the theoretical thermal resistances; calculating error between measured data and simulation results is no more than ±7%. Thus, the Hi-LED illumination lamp has high life cycle and reliability.

  7. Robust, Rework-able Thermal Electronic Packaging: Applications in High Power TR Modules for Space

    Science.gov (United States)

    Hoffman, James Patrick; Del Castillo, Linda; Hunter, Don; Miller, Jennifer

    2012-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires improvements in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and are now being implemented side-by-side with more standard technology typically used in flight hardware.

  8. A 3D Lumped Thermal Network Model for Long-term Load Profiles Analysis in High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Ghimire, Pramod

    2016-01-01

    )-based simulation is another method which is often used to analyze the steady-state thermal distribution of IGBT modules, but it is not possible to be used for long-term analysis of load profiles of power converter, which is needed for reliability assessments and better thermal design. This paper proposes a novel...... enables both accurate and fast temperature estimation of high power IGBT modules in the real loading conditions of the converter; meanwhile the critical details of the thermal dynamics and thermal distribution are also maintained. The proposed thermal model is verified by both FEM simulation......The conventional RC lumped thermal networks are widely used to estimate the temperature of power devices, but they are lack of accuracy in addressing detailed thermal behaviors/couplings in different locations and layers of the high power IGBT modules. On the other hand, Finite Element (FE...

  9. A Novel 3D Thermal Impedance Model for High Power Modules Considering Multi-layer Thermal Coupling and Different Heating/Cooling Conditions

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2015-01-01

    accurate temperature estimation either vertically or horizontally inside the power devices is still hard to identify. This paper investigates the thermal behavior of high power module in various operating conditions by means of Finite Element Method (FEM). A novel 3D thermal impedance network considering......Thermal management of power electronic devices is essential for reliable performance especially at high power levels. One of the most important activities in the thermal management and reliability improvement is acquiring the temperature information in critical points of the power module. However...

  10. ICRF power deposition profile and determination of the electron thermal diffusivity by modulation experiments in JET

    International Nuclear Information System (INIS)

    Gambier, D.J.; Evrard, M.P.; Adam, J.

    1990-01-01

    The power deposition profile in the ion cyclotron range of frequencies (ICRF) has been investigated experimentally in JET by means of a square wave modulated RF perturbation. The study has been conducted in D(H) and D( 3 He) plasmas for two heating scenarios. In D( 3 He) plasmas and for central heating in a scenario where mode conversion to Bernstein waves is accessible, the direct power deposition profile on electrons has been derived. It accounts for 15% of the total coupled power and extends over 25% of the minor radius. Outside the RF power deposition zone, the electron thermal diffusivity χ e inside the inversion radius surface (r i ) can be estimated through observation of the diffusive electronic transport. In discharges without monster sawteeth and for a low central temperature gradient (∇T e (r ≤ r i ) ≤ ∇T e (r ≥ r i ) approx. = 5 keV·m -1 ) the value obtained is small (approx. =0.24 +- 0.05 m 2 · s -1 ), typically ten times lower than χ e values deduced from heat pulse propagation in similar discharges at radii larger than the inversion radius. For the D(H) minority heating scheme, a large fraction of the ICRF modulated power is absorbed by minority ions, and the minority tail is modulated with a characteristic ion-electron (i-e) slowing-down time. In this scheme, electron heating occurs only through collisions with the minority ion tail and no modulation of the electron temperature is observed in sawtoothing discharges. This is interpreted as a consequence of the long i-e equipartition time, acting as an integrator for the modulated ICRF signal. Finally, a correlation between the time of the sawtooth crash and the periodic turn-off of the ICRF power is found and its consequence for modulation experiments is reviewed. (author). 22 refs, 16 figs

  11. Pump and Flow Control Subassembly of Thermal Control Subsystem for Photovoltaic Power Module

    Science.gov (United States)

    Motil, Brian; Santen, Mark A.

    1993-01-01

    The pump and flow control subassembly (PFCS) is an orbital replacement unit (ORU) on the Space Station Freedom photovoltaic power module (PVM). The PFCS pumps liquid ammonia at a constant rate of approximately 1170 kg/hr while providing temperature control by flow regulation between the radiator and the bypass loop. Also, housed within the ORU is an accumulator to compensate for fluid volumetric changes as well as the electronics and firmware for monitoring and control of the photovoltaic thermal control system (PVTCS). Major electronic functions include signal conditioning, data interfacing and motor control. This paper will provide a description of each major component within the PFCS along with performance test data. In addition, this paper will discuss the flow control algorithm and describe how the nickel hydrogen batteries and associated power electronics will be thermally controlled through regulation of coolant flow to the radiator.

  12. Thermal Equilibrium Dynamic Control Based on DPWM Dual-Mode Modulation of High Power NPC Three-Level Inverter

    Directory of Open Access Journals (Sweden)

    Shi-Zhou Xu

    2016-01-01

    Full Text Available In some special applications of NPC three-level inverters, such as mine hoist, there exist special conditions of overloading during the whole hoisting process and large overload in starting stage, during which the power-loss calculation of power devices and thermal control are important factors affecting the thermal stability of inverters. The principles of SVPWM and DPWM were described in this paper firstly, based on which the dynamic power losses of the two modulations of hoist in single period were calculated. Secondly, a thermal equilibrium dynamic control based on DPMW dual-mode modulation was proposed, which can switch the modulation dynamically according to the change of dynamic power loss to realize dynamic control of power loss and thermal equilibrium of inverter. Finally, simulation and experiment prove the effectiveness of the proposed strategy.

  13. Thermal fatigue life evaluation of SnAgCu solder joints in a multi-chip power module

    Science.gov (United States)

    Barbagallo, C.; Malgioglio, G. L.; Petrone, G.; Cammarata, G.

    2017-05-01

    For power devices, the reliability of thermal fatigue induced by thermal cycling has been prioritized as an important concern. The main target of this work is to apply a numerical procedure to assess the fatigue life for lead-free solder joints, that represent, in general, the weakest part of the electronic modules. Starting from a real multi-chip power module, FE-based models were built-up by considering different conditions in model implementation in order to simulate, from one hand, the worst working condition for the module and, from another one, the module standing into a climatic test room performing thermal cycles. Simulations were carried-out both in steady and transient conditions in order to estimate the module thermal maps, the stress-strain distributions, the effective plastic strain distributions and finally to assess the number of cycles to failure of the constitutive solder layers.

  14. Thermal fatigue life evaluation of SnAgCu solder joints in a multi-chip power module

    International Nuclear Information System (INIS)

    Barbagallo, C; Petrone, G; Cammarata, G; Malgioglio, G L

    2017-01-01

    For power devices, the reliability of thermal fatigue induced by thermal cycling has been prioritized as an important concern. The main target of this work is to apply a numerical procedure to assess the fatigue life for lead-free solder joints, that represent, in general, the weakest part of the electronic modules. Starting from a real multi-chip power module, FE-based models were built-up by considering different conditions in model implementation in order to simulate, from one hand, the worst working condition for the module and, from another one, the module standing into a climatic test room performing thermal cycles. Simulations were carried-out both in steady and transient conditions in order to estimate the module thermal maps, the stress-strain distributions, the effective plastic strain distributions and finally to assess the number of cycles to failure of the constitutive solder layers. (paper)

  15. Thermal Equilibrium Dynamic Control Based on DPWM Dual-Mode Modulation of High Power NPC Three-Level Inverter

    OpenAIRE

    Xu, Shi-Zhou; He, Feng-You

    2016-01-01

    In some special applications of NPC three-level inverters, such as mine hoist, there exist special conditions of overloading during the whole hoisting process and large overload in starting stage, during which the power-loss calculation of power devices and thermal control are important factors affecting the thermal stability of inverters. The principles of SVPWM and DPWM were described in this paper firstly, based on which the dynamic power losses of the two modulations of hoist in single pe...

  16. In-Situ Measurement of Power Loss for Crystalline Silicon Modules Undergoing Thermal Cycling and Mechanical Loading Stress Testing

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso

    We analyze the degradation of multi-crystalline silicon photovoltaic modules undergoing simultaneous thermal, mechanical, and humidity-freeze stress testing to develop a dark environmental chamber in-situ measurement procedure for determining module power loss. We analyze dark I-V curves measured...

  17. Application of pulsed power and power modulation to the non-thermal plasma treatment of hazardous gaseous wastes

    International Nuclear Information System (INIS)

    Penetrante, B.M.

    1992-10-01

    Acid rain, global warming, ozone depletion, and smog are preeminent environmental problems facing the world today. Non-thermal plasma techniques offer an innovative approach to the cost-effective solution of these problems. Many potential applications of non-thermal plasmas to air pollution control have already been demonstrated. The use of pulsed power and power modulation is essential to the successful implementation of non-thermal plasma techniques. This paper provides an overview of the most recent developments in non-thermal plasma systems that have been applied to gaseous waste treatment. In the non-thermal plasma approach, the nonequilibrium properties of the plasma are fully exploited. These plasmas are characterized by high electron temperatures, while the gas remains at near ambient temperature and pressure. The energy is directed preferentially to the undesirable components, which are often present in very small concentrations. These techniques utilize the dissociation and ionization of the background gas to produce radicals which, in turn, decompose the toxic compounds. The key to success in the non-thermal plasma approach is to produce a discharge in which the majority of the electrical energy goes into the production of energetic electrons, rather than into gas heating. For example, in a typical application to flue gas cleanup, these electrons produce radicals, such as O and OH, through the dissociation or ionization of molecules such as H 2 O or O 2 . The radicals diffuse through the gas and preferentially oxidize the nitrogen oxides and sulfur oxides to form acids that can then be easily neutralized to form non-toxic, easily-collectible (and commercially salable) compounds. Non-thermal plasmas can be created in essentially two different ways: by electron-beam irradiation, and by electrical discharges

  18. Thermal Modeling of NUHOMS HSM-15 and HSM-1 Storage Modules at Calvert Cliffs Nuclear Power Station ISFSI

    Energy Technology Data Exchange (ETDEWEB)

    Suffield, Sarah R.; Fort, James A.; Adkins, Harold E.; Cuta, Judith M.; Collins, Brian A.; Siciliano, Edward R.

    2012-10-01

    As part of the Used Fuel Disposition Campaign of the Department of Energy (DOE), visual inspections and temperature measurements were performed on two storage modules in the Calvert Cliffs Nuclear Power Station’s Independent Spent Fuel Storage Installation (ISFSI). Detailed thermal models models were developed to obtain realistic temperature predictions for actual storage systems, in contrast to conservative and bounding design basis calculations.

  19. Compact electro-thermal modeling of a SiC MOSFET power module under short-circuit conditions

    DEFF Research Database (Denmark)

    Ceccarelli, Lorenzo; Reigosa, Paula Diaz; Bahman, Amir Sajjad

    2017-01-01

    A novel physics-based, electro-thermal model which is capable of estimating accurately the short-circuit behavior and thermal instabilities of silicon carbide MOSFET multi-chip power modules is proposed in this paper. The model has been implemented in PSpice and describes the internal structure.......2 kV breakdown voltage and about 300 A rated current. The short-circuit behavior of the module is investigated experimentally through a non-destructive test setup and the model is validated. The estimation of overcurrent and temperature distribution among the chips can provide useful information...

  20. Electrical Parasitics and Thermal Modeling for Optimized Layout Design of High Power SiC Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Blaabjerg, Frede; Dutta, Atanu

    2016-01-01

    , the presented models are verified by a conventional and an optimized power module layout. The optimized layout is designed based on the reduction of stray inductance and temperature in a P-cell and N-cell half-bridge module. The presented models are verified by FEM simulations and also experiment....

  1. Electro-thermal modeling of high power IGBT module short-circuits with experimental validation

    DEFF Research Database (Denmark)

    Wu, Rui; Iannuzzo, Francesco; Wang, Huai

    2015-01-01

    A novel Insulated Gate Bipolar Transistor (IGBT) electro-thermal modeling approach involving PSpice and ANSYS/Icepak with both high accuracy and simulation speed has been presented to study short-circuit of a 1.7 kV/1 kA commercial IGBT module. The approach successfully predicts the current...

  2. Simplified Thermal Modeling for IGBT Modules with Periodic Power Loss Profiles in Modular Multilevel Converters

    DEFF Research Database (Denmark)

    Zhang, Yi; Wang, Huai; Wang, Zhongxu

    2018-01-01

    One of the future challenges in Modular Multilevel Converters (MMCs) is how to size key components with compromised costs and design margins while fulfilling specific reliability targets. It demands better thermal modeling compared to the state-of-the-art in terms of both accuracy and simplicity....... Different from two-level power converters, MMCs have inherent dc-bias in arm currents and the power device conduction time is affected by operational parameters. A time-wise thermal modeling for the power devices in MMCs is, therefore, an iteration process and time-consuming. This paper thus proposes...

  3. Solar Thermal Power.

    Science.gov (United States)

    McDaniels, David K.

    The different approaches to the generation of power from solar energy may be roughly divided into five categories: distributed collectors; central receivers; biomass; ocean thermal energy conversion; and photovoltaic devices. The first approach (distributed collectors) is the subject of this module. The material presented is designed to…

  4. Passive Sun seeker/tracker and a thermally activated power module

    Science.gov (United States)

    Siebert, C. J.; Morris, F. A.

    1984-01-01

    Development and testing of two mechanisms using a shape memory alloy metal (NITINOL) as the power source are described. The two mechanisms developed are a passive Sun Seeker/Tracker and a generic type power module. These mechanisms use NITINOL wire initially strained in pure torsion which provides the greatest mechanical work capacity upon recovery, as compared to other deformation modes (i.e., tension, helical springs, and bending).

  5. A review of test results on solar thermal power modules with dish-mounted Stirling and Brayton cycle engines

    Science.gov (United States)

    Jaffe, Leonard D.

    1988-01-01

    This paper presents results of development tests of various solar thermal parabolic dish modules and assemblies that used dish-mounted Brayton or Stirling cycle engines for production of electric power. These tests indicate that early modules achieve net efficiencies up to 29 percent in converting sunlight to electricity, as delivered to the grid. Various equipment deficiencies were observed and a number of malfunctions occurred. The performance measurements, as well as the malfunctions and other test experience, provided information that should be of value in developing systems with improved performance and reduced maintenance.

  6. A review of test results on solar thermal power modules with dish-mounted Stirling and Brayton cycle engines

    Science.gov (United States)

    Jaffe, Leonard D.

    1988-11-01

    This paper presents results of development tests of various solar thermal parabolic dish modules and assemblies that used dish-mounted Brayton or Stirling cycle engines for production of electric power. These tests indicate that early modules achieve net efficiencies up to 29 percent in converting sunlight to electricity, as delivered to the grid. Various equipment deficiencies were observed and a number of malfunctions occurred. The performance measurements, as well as the malfunctions and other test experience, provided information that should be of value in developing systems with improved performance and reduced maintenance.

  7. Test results of an organic Rankine-cycle power module for a small community solar thermal power experiment

    Science.gov (United States)

    Clark, T. B.

    1985-01-01

    The organic Rankine-cycle (ORC) power conversion assembly was tested. Qualification testing of the electrical transport subsystem was also completed. Test objectives were to verify compatibility of all system elements with emphasis on control of the power conversion assembly, to evaluate the performance and efficiency of the components, and to validate operating procedures. After 34 hours of power generation under a wide range of conditions, the net module efficiency exceeded 18% after accounting for all parasitic losses.

  8. Study on the Thermal Resistance of Multi-chip Module High Power LED Packaging Heat Dissipation System

    Directory of Open Access Journals (Sweden)

    Kailin Pan

    2014-10-01

    Full Text Available Thermal resistance is a key technical index which indicates the thermal management of multi-chip module high power LED (MCM-LED packaging heat dissipation system. In this paper, the prototype structure of MCM-LED packaging heat dissipation system is proposed to study the reliable thermal resistance calculation method. In order to analyze the total thermal resistance of the MCM-LED packaging heat dissipation system, three kinds of thermal resistance calculation method including theoretical calculation, experimental testing and finite element simulation are developed respectively. Firstly, based on the thermal resistance network model and the principle of steady state heat transfer, the theoretical value of total thermal resistance is 6.111 K/W through sum of the thermal resistance of every material layer in the major direction of heat flow. Secondly, the thermal resistance experiment is carried out by T3Ster to obtain the experimental result of total thermal resistance, and the value is 6.729 K/W. Thirdly, a three-dimensional finite element model of MCM-LED packaging heat dissipation system is established, and the junction temperature experiment is also performed to calculated the finite element simulated result of total thermal resistance, the value is 6.99 K/W. Finally, by comparing the error of all the three kinds of result, the error of total thermal resistance between the theoretical value and experimental result is 9.2 %, and the error of total thermal resistance between the experimental result and finite element simulation is only about -3.9 %, meanwhile, the main reason of each error is discussed respectively.

  9. Thermal management of cylindrical power battery module for extending the life of new energy electric vehicles

    International Nuclear Information System (INIS)

    Zhao, Jiateng; Rao, Zhonghao; Huo, Yutao; Liu, Xinjian; Li, Yimin

    2015-01-01

    Thermal management especially cooling plays an important role in power battery modules for electric vehicles. In order to comprehensively understand the heat transfer characteristics of air cooling system, the air cooling numerical simulation battery models for cylindrical lithium-ion power battery pack were established in this paper, and a detailed parametric investigation was undertaken to study effects of different ventilation types and velocities, gap spacing between neighbor batteries, temperatures of environment and entrance air, amount of single row cells and battery diameter on the thermal management performance of battery pack. The results showed that the local temperature difference increased firstly and then decreased with the increase of wind speed. Reversing the air flow direction between adjacent rows is not necessarily appropriate and the gap spacing should not be too small and too large. It is prone to thermal runaway when the ambient temperature is too high, and the most suitable value of S/D (the ratio of spacing distance between neighbor cells and cell diameter) is gradually reduced along with the increase of cell diameter. - Highlights: • Air cooling models were established for cylindrical lithium-ion power battery pack. • Local temperature difference increased firstly and then decreased with wind speed. • The gap spacing size of battery pack should not be too small and too large. • It is prone to thermal runaway when the ambient temperature is too high. • The ratio of S/D is gradually reduced with the increase of cell diameter

  10. Experimental studies for improvement of thermal effects in a high-power fiber-coupled diode laser module operating at 808 nm

    Science.gov (United States)

    El-Sherif, Ashraf F.; Hussein, Khalid; Hassan, Mahmoud F.; Talat, Mahmoud M.

    2012-03-01

    High power diode laser module operating at 808 nm is required for different applications, such as developing an efficient high power Nd3+-doped solid state laser and Tm3+ -doped silica fiber laser, industrial, medical and military applications. Optical and thermal images characterization for a fiber-coupled high power diode laser module is presented experimentally for 6.6 Watt output optical power .An external temperature controller system was designed, which stabilizes the central wavelength at 808 nm at 25°C over a wide range of diode laser driving current from 1A to 6 A. without this cooling system, the wavelength changes by 0.35nm/°C for temperature changes from 20°C to 40°C at the same range of the driving current. In this paper we have present a methodology for temperature reduction of a 808 nm high power diode laser module, based on dynamically thermal control, which is known as dynamic thermal management. Stabilization of the output wavelength has been done by using proportional speed control (PSC) of a CPU cooling fan with certain scheme of straight fins heat sink. Two electronic circuits based on pulse width modulation (PWM) in microcontroller and comparators IC have been used. This technique can be considered as an effective mechanism for reducing temperature and power dissipation to make stabilization of the diode laser output wavelength by preventing heat accumulation from the thermo electric cooling (TEC) inside the diode laser module confirmed by thermal images.

  11. The electrical, thermal and spatial integration of a converter in a power electronic module

    NARCIS (Netherlands)

    Gerber, M.B.

    2005-01-01

    This thesis is concerned with the design and implementation of a power electronic system (14/42V DC/DC converter) that is implemented in the automotive environment, specifically the engine compartment. The power electronic system must have a high power density while operating in a high temperature

  12. Evaluation of thermal performance of all-GaN power module in parallel operation

    International Nuclear Information System (INIS)

    Chou, Po-Chien; Cheng, Stone; Chen, Szu-Hao

    2014-01-01

    This work presents an extensive thermal characterization of a single discrete GaN high-electron-mobility transistor (HEMT) device when operated in parallel at temperatures of 25 °C–175 °C. The maximum drain current (I D max ), on-resistance (R ON ), pinch-off voltage (V P ) and peak transconductance (g m ) at various chamber temperatures are measured and correlations among these parameters studied. Understanding the dependence of key transistor parameters on temperature is crucial to inhibiting the generation of hot spots and the equalization of currents in the parallel operation of HEMTs. A detailed analysis of the current imbalance between two parallel HEMT cells and its consequential effect on the junction temperature are also presented. The results from variations in the characteristics of the parallel-connected devices further verify that the thermal stability and switching behavior of these cells are balanced. Two parallel HEMT cells are operated at a safe working distance from thermal runaway to prevent destruction of the hottest cell. - Highlights: • This work reveals the sorting process of GaN devices for parallel operation. • The variations of I D max , R ON , V P , and g m with temperature are established. • The temperature-dependence parameters are crucial to prevent hot spots generation. • Safe working operation prevents thermal runaway and hottest cell destruction

  13. Thermal Efficiency of Power Module “Boiler with Solar Collectors as Additional Heat Source” For Combined Heat Supply System

    Directory of Open Access Journals (Sweden)

    Denysova A.E.

    2015-04-01

    Full Text Available The purpose of work is to increase the efficiency of the combined heat supply system with solar collectors as additional thermal generators. In order to optimize the parameters of combined heat supply system the mathematical modeling of thermal processes in multi module solar collectors as additional thermal generators for preheating of the water for boiler have been done. The method of calculation of multi-module solar collectors working with forced circulation for various configurations of hydraulic connection of solar collector modules as the new result of our work have been proposed. The results of numerical simulation of thermal efficiency of solar heat source for boiler of combined heat supply system with the account of design features of the circuit; regime parameters of thermal generators that allow establishing rational conditions of its functioning have been worked out. The conditions of functioning that provide required temperature of heat carrier incoming to boiler and value of flow rate at which the slippage of heat carrier is not possible for different hydraulic circuits of solar modules have been established.

  14. Power module assembly

    Science.gov (United States)

    Campbell, Jeremy B [Torrance, CA; Newson, Steve [Redondo Beach, CA

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  15. Power module assemblies with staggered coolant channels

    Science.gov (United States)

    Herron, Nicholas Hayden; Mann, Brooks S; Korich, Mark D

    2013-07-16

    A manifold is provided for supporting a power module assembly with a plurality of power modules. The manifold includes a first manifold section. The first face of the first manifold section is configured to receive the first power module, and the second face of the first manifold section defines a first cavity with a first baseplate thermally coupled to the first power module. The first face of the second manifold section is configured to receive the second power module, and the second face of the second manifold section defines a second cavity with a second baseplate thermally coupled to the second power module. The second face of the first manifold section and the second face of the second manifold section are coupled together such that the first cavity and the second cavity form a coolant channel. The first cavity is at least partially staggered with respect to second cavity.

  16. Solar dynamic power module design

    Science.gov (United States)

    Secunde, Richard R.; Labus, Thomas L.; Lovely, Ronald G.

    1989-01-01

    Studies have shown that the use of solar dynamic (SD) power for the growth areas of the Space Station Freedom program will result in life cycle cost savings when compared to power supplied by photovoltaic sources. In the SD power module, a concentrator collects and focuses solar energy into a heat receiver which has integral thermal energy storage. A Power Conversion Unit (PCU) based on the closed Brayton cycle removes thermal energy from the receiver and converts that energy to electrical energy. Since the closed Brayton cycle is a single phase gas cycle, the conversion hardware (heat exchangers, turbine, compressor, etc.) can be designed for operation in low earth orbit, and tested with confidence in test facilities on earth before launch into space. The concentrator subassemblies will be aligned and the receiver/PCU/radiator combination completely assembled and charged with gas and cooling liquid on earth before launch to, and assembly on, orbit.

  17. Power Electronics Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilberto [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-07

    Thermal modeling was conducted to evaluate and develop thermal management strategies for high-temperature wide-bandgap (WBG)-based power electronics systems. WBG device temperatures of 175 degrees C to 250 degrees C were modeled under various under-hood temperature environments. Modeling result were used to identify the most effective capacitor cooling strategies under high device temperature conditions.

  18. Solar thermal power plants

    International Nuclear Information System (INIS)

    Schnatbaum, L.

    2009-01-01

    The solar thermal power plant technology, the opportunities it presents and the developments in the market are outlined. The focus is on the technology of parabolic trough power plants, a proven technology for solar power generation on a large scale. In a parabolic trough power plant, trough-shaped mirrors concentrate the solar irradiation onto a pipe in the focal line of the collector. The thermal energy thus generated is used for electricity generation in a steam turbine. Parabolic trough plants can be combined with thermal storage and fossil or biomass fired heat exchangers to generate electricity even when the sun is not shining. Solar Millennium AG in Erlangen has developed the first power plant of this kind in Europe. After two years of construction the plant started operation in Southern Spain in 2008. This one and its sister projects are important steps leading the way for the whole market. The paper also covers the technological challenges, the key components used and the research and development activities concerning this technology. Solar thermal power plants are ideal for covering peak and medium loads in power grids. In hybrid operation they can also cover base-load. The Solar Chimney power plant, another striking technology for the conversion of solar into electric energy, is described briefly. The paper concludes with a look at the future - the import of solar energy from the deserts of North Africa to central Europe. (author)

  19. Pulse power modulators - an overview

    International Nuclear Information System (INIS)

    Venkatramani, N.

    2006-01-01

    Pulse power modulators are electronic devices to provide, high voltage, high current, power bursts. Ideally, a modulator, with the means to shape and control the pulses, acts as a switch between a high voltage power supply and its load. This article gives an overview of the pulse power modulators: starting with the basics of pulse and modulation, it covers modulation topologies, different types of modulators, major subsystems and pulse measurement techniques. The various applications of pulse power modulators and the recent trends have been included at the end. (author)

  20. Modulation Methods for Neutral-Point-Clamped Wind Power Converter Achieving Loss and Thermal Redistribution Under Low-Voltage Ride-Through

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede

    2014-01-01

    The three-level neutral-point (NP)-clamped (3L-NPC) converter is a promising multilevel topology in the application of megawatt wind power generation systems. However, the growing requirements by grid codes may impose high stress and even give reliability problem to this converter topology......, with the proposed modulation methods, the thermal distribution in the 3L-NPC wind power inverter undergoing LVRT becomes more equal, and the junction temperature of the most stressed devices can be also relieved. Also, the control ability of the dc-bus NP potential, which is one of the crucial considerations...

  1. Loss and thermal redistributed modulation methods for three-level neutral-point-clamped wind power inverter undergoing Low Voltage Ride Through

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede

    2012-01-01

    The three-level neutral-point-clamped (3L-NPC) converter is a promising multilevel topology in the application of mega-watts wind power generation system. However, the growing requirements by grid codes may impose high stress and even give reliability problem to this converter topology. This paper...... modulation methods, the thermal distribution in the 3L-NPC wind power inverter undergoing LVRT becomes more equal, and the junction temperature of the most stressed devices can be also relieved. Also the control ability of DC-bus neutral point potential, which is one of the crucial considerations for the 3L...

  2. Performance Characterisation of a Hybrid Flat-Plate Vacuum Insulated Photovoltaic/Thermal Solar Power Module in Subtropical Climate

    Directory of Open Access Journals (Sweden)

    Andrew Y. A. Oyieke

    2016-01-01

    Full Text Available A flat-plate Vacuum Insulated Photovoltaic and Thermal (VIPV/T system has been thermodynamically simulated and experimentally evaluated to assess the thermal and electrical performance as well as energy conversion efficiencies under a subtropical climate. A simulation model made of specified components is developed in Transient Systems (TRNSYS environment into which numerical energy balance equations are implemented. The influence of vacuum insulation on the system’s electrical and thermal yields has been evaluated using temperatures, current, voltage, and power flows over daily and annual cycles under local meteorological conditions. The results from an experiment conducted under steady-state conditions in Durban, South Africa, are compared with the simulation based on the actual daily weather data. The VIPV/T has shown improved overall and thermal efficiencies of 9.5% and 16.8%, respectively, while electrical efficiency marginally reduced by 0.02% compared to the conventional PV/T. The simulated annual overall efficiency of 29% (i.e., 18% thermal and 11% electrical has been realised, in addition to the solar fraction, overall exergy, and primary energy saving efficiencies of 39%, 29%, and 27%, respectively.

  3. A review of test results on parabolic dish solar thermal power modules with dish-mounted Rankine engines and for production of process steam

    Science.gov (United States)

    Jaffe, Leonard D.

    1988-11-01

    This paper presents results of development testing of various solar thermal parabolic dish modules and assemblies. Most of the tests were at modules and assemblies that used a dish-mounted, organic Rankine cycle turbine for production of electric power. Some tests were also run on equipment for production of process steam or for production of electricity using dish-mounted reciprocating steam engines. These tests indicate that early modules achieve efficiencies of about 18 percent in converting sunlight to electricity (excluding the inverter but including parasitics). A number of malfunctions occurred. The performance measurements, as well as the malfunctions and other operating experience, provided information that should be of value in developing systems with improved performance and reduced maintenance.

  4. Thermal power measurement apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Thermal power measurements are important in nuclear power plants, fossil-fuel plants and other closed loop systems such as heat exchangers and chemical reactors. The main object of this invention is to determine the enthalpy of a fluid using only acoustically determined sound speed and correlating the speed with enthalpy. An enthalpy change is measured between two points in the fluid flow: the apparatus is described in detail. (U.K.)

  5. Temperature Modulated Nanomechanical Thermal Analysis

    DEFF Research Database (Denmark)

    Alves, Gustavo Marcati A.; Bose-Goswami, Sanjukta; Mansano, Ronaldo D.

    2018-01-01

    The response of microcantilever deflection to complex heating profiles was used to study thermal events like glass transition and enthalpy relaxation on nanograms of the biopolymer Poly(lactic-co-glycolic acid) (PLGA). The use of two heating rates enables the separation of effects on the deflection...... response that depends on previous thermal history (non-reversing signal) and effects that depends only on the heating rate variation (reversing signal). As these effects may appear superposed in the total response, temperature modulation can increase the measurement sensitivity to some thermal events when...

  6. Investigation of the thermal and optical performance of a spatial light modulator with high average power picosecond laser exposure for materials processing applications

    Science.gov (United States)

    Zhu, G.; Whitehead, D.; Perrie, W.; Allegre, O. J.; Olle, V.; Li, Q.; Tang, Y.; Dawson, K.; Jin, Y.; Edwardson, S. P.; Li, L.; Dearden, G.

    2018-03-01

    Spatial light modulators (SLMs) addressed with computer generated holograms (CGHs) can create structured light fields on demand when an incident laser beam is diffracted by a phase CGH. The power handling limitations of these devices based on a liquid crystal layer has always been of some concern. With careful engineering of chip thermal management, we report the detailed optical phase and temperature response of a liquid cooled SLM exposed to picosecond laser powers up to 〈P〉  =  220 W at 1064 nm. This information is critical for determining device performance at high laser powers. SLM chip temperature rose linearly with incident laser exposure, increasing by only 5 °C at 〈P〉  =  220 W incident power, measured with a thermal imaging camera. Thermal response time with continuous exposure was 1-2 s. The optical phase response with incident power approaches 2π radians with average power up to 〈P〉  =  130 W, hence the operational limit, while above this power, liquid crystal thickness variations limit phase response to just over π radians. Modelling of the thermal and phase response with exposure is also presented, supporting experimental observations well. These remarkable performance characteristics show that liquid crystal based SLM technology is highly robust when efficiently cooled. High speed, multi-beam plasmonic surface micro-structuring at a rate R  =  8 cm2 s-1 is achieved on polished metal surfaces at 〈P〉  =  25 W exposure while diffractive, multi-beam surface ablation with average power 〈P〉  =100 W on stainless steel is demonstrated with ablation rate of ~4 mm3 min-1. However, above 130 W, first order diffraction efficiency drops significantly in accord with the observed operational limit. Continuous exposure for a period of 45 min at a laser power of 〈P〉  =  160 W did not result in any detectable drop in diffraction efficiency, confirmed afterwards by the efficient

  7. Power electronic modules design and manufacture

    CERN Document Server

    Sheng, William W

    2004-01-01

    IntroductionSelection ProcedureMaterialsInsulating Substrate and MetallizationBase PlateBonding MaterialPower Interconnection and TerminalEncapsulantPlastic Case and Cover Manufacturing of Power IGBT ModulesManufacturing Process Process Control/Long-Term ReliabilityManufacturing FacilitiesManufacturing Flow Charts DesignThermal ManagementCircuit PartitioningDesign Guidelines and ConsiderationsThermal Results of Different Samples

  8. Concentrating solar thermal power.

    Science.gov (United States)

    Müller-Steinhagen, Hans

    2013-08-13

    In addition to wind and photovoltaic power, concentrating solar thermal power (CSP) will make a major contribution to electricity provision from renewable energies. Drawing on almost 30 years of operational experience in the multi-megawatt range, CSP is now a proven technology with a reliable cost and performance record. In conjunction with thermal energy storage, electricity can be provided according to demand. To date, solar thermal power plants with a total capacity of 1.3 GW are in operation worldwide, with an additional 2.3 GW under construction and 31.7 GW in advanced planning stage. Depending on the concentration factors, temperatures up to 1000°C can be reached to produce saturated or superheated steam for steam turbine cycles or compressed hot gas for gas turbine cycles. The heat rejected from these thermodynamic cycles can be used for sea water desalination, process heat and centralized provision of chilled water. While electricity generation from CSP plants is still more expensive than from wind turbines or photovoltaic panels, its independence from fluctuations and daily variation of wind speed and solar radiation provides it with a higher value. To become competitive with mid-load electricity from conventional power plants within the next 10-15 years, mass production of components, increased plant size and planning/operating experience will be accompanied by technological innovations. On 30 October 2009, a number of major industrial companies joined forces to establish the so-called DESERTEC Industry Initiative, which aims at providing by 2050 15 per cent of European electricity from renewable energy sources in North Africa, while at the same time securing energy, water, income and employment for this region. Solar thermal power plants are in the heart of this concept.

  9. Power Electronics Thermal Management R&D

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilbert; Bennion, Kevin

    2016-06-08

    This project will develop thermal management strategies to enable efficient and high-temperature wide-bandgap (WBG)-based power electronic systems (e.g., emerging inverter and DC-DC converter designs). The use of WBG-based devices in automotive power electronics will improve efficiency and increase driving range in electric-drive vehicles; however, the implementation of this technology is limited, in part, due to thermal issues. This project will develop system-level thermal models to determine the thermal limitations of current automotive power modules under elevated device temperature conditions. Additionally, novel cooling concepts and material selection will be evaluated to enable high-temperature silicon and WBG devices in power electronics components. WBG devices (silicon carbide [SiC], gallium nitride [GaN]) promise to increase efficiency, but will be driven as hard as possible. This creates challenges for thermal management and reliability.

  10. Solar thermal power system

    Science.gov (United States)

    Bennett, Charles L.

    2010-06-15

    A solar thermal power generator includes an inclined elongated boiler tube positioned in the focus of a solar concentrator for generating steam from water. The boiler tube is connected at one end to receive water from a pressure vessel as well as connected at an opposite end to return steam back to the vessel in a fluidic circuit arrangement that stores energy in the form of heated water in the pressure vessel. An expander, condenser, and reservoir are also connected in series to respectively produce work using the steam passed either directly (above a water line in the vessel) or indirectly (below a water line in the vessel) through the pressure vessel, condense the expanded steam, and collect the condensed water. The reservoir also supplies the collected water back to the pressure vessel at the end of a diurnal cycle when the vessel is sufficiently depressurized, so that the system is reset to repeat the cycle the following day. The circuital arrangement of the boiler tube and the pressure vessel operates to dampen flow instabilities in the boiler tube, damp out the effects of solar transients, and provide thermal energy storage which enables time shifting of power generation to better align with the higher demand for energy during peak energy usage periods.

  11. Thermal electric power production

    International Nuclear Information System (INIS)

    Boehmer, S.

    2001-01-01

    The basic principle of a thermal power plant is to heat up water in the pipe system of a boiler to generate steam, which exits the boiler with high pressure and releases its energy to a tandem-arranged turbine. This energy is transmitted to a generator over a common shaft. The generated electricity is fed into the power supply system. The processed steam is condensed to water by means of a condenser and transferred back into the pipe system of the boiler (feed water circuit). In general the following techniques are applied for the combustion of solid, liquid and gaseous fuels: dry bottom boiler, wet bottom boiler, grate firing, fluidized bed combustion, gasification systems - integrated gasification combined cycle (IGCC), oil firing technique, gas firing technique. Residues from power plants are generated by the following processes and emission reduction measures: separation of bottom ash or boiler slag in the boiler; separation of fly ash (particulate matter) by means of filters or electric precipitators; desulphurization through lime additive processes, dry sorption or spray absorption processes and lime scrubbing processes; desulphurization according to Wellmann-Lord and to the Walther process; reduction of NO x emissions by selective catalytic reduction (SCR). In this case spent catalyst results as a waste unless it is recycled. No residues are generated by the following measures to reduce NO x emissions: minimization of nitrogen by selective non-catalytic reduction (SNCR); adaptations of the firing technology to avoid emissions - primary measures (low-NO x burners, CO reduction). However, this may change the quality of fly ash by increasing unburnt carbon. Combustion of fossil fuels (with the exception of gaseous fuels) and biomass generates large quantities of residues - with coal being the greatest contributor - either from the fuel itself in the form of ashes, or from flue gas cleaning measures. In coal-fired power plants huge amounts of inorganic residues

  12. AND THERMAL POWER PLANTS

    Directory of Open Access Journals (Sweden)

    Alduhov Oleg Aleksandrovich

    2012-10-01

    Full Text Available Investigation of the atmospheric dispersion as part of the process of selection of sites to accommodate nuclear and thermal power plants is performed to identify concentration fields of emissions and to assess the anthropogenic impact produced on the landscape components and human beings. Scattering properties of the atmospheric boundary layer are mainly determined by the turbulence intensity and the wind field. In its turn, the turbulence intensity is associated with the thermal stratification of the boundary layer. Therefore, research of the atmospheric dispersion is reduced to the study of temperature and wind patterns of the boundary layer. Statistical processing and analysis of the upper-air data involves the input of the data collected by upper-air stations. Until recently, the upper-air data covering the standard period between 1961 and 1970 were applied for these purposes, although these data cannot assure sufficient reliability of assessments in terms of the properties of the atmospheric dispersion. However, recent scientific and technological developments make it possible to substantially increase the data coverage by adding the upper-air data collected within the period between 1964 and 2010. The article has a brief overview of BL_PROGS, a specialized software package designated for the processing of the above data. The software package analyzes the principal properties of the atmospheric dispersion. The use of the proposed software package requires preliminary development of a database that has the information collected by an upper-air station. The software package is noteworthy for the absence of any substantial limitations imposed onto the amount of the input data that may go up in proportion to the amount of the upper-air data collected by upper-air stations.

  13. Solar thermal aided power generation

    International Nuclear Information System (INIS)

    Hu, Eric; Yang, YongPing; Nishimura, Akira; Yilmaz, Ferdi; Kouzani, Abbas

    2010-01-01

    Fossil fuel based power generation is and will still be the back bone of our world economy, albeit such form of power generation significantly contributes to global CO 2 emissions. Solar energy is a clean, environmental friendly energy source for power generation, however solar photovoltaic electricity generation is not practical for large commercial scales due to its cost and high-tech nature. Solar thermal is another way to use solar energy to generate power. Many attempts to establish solar (solo) thermal power stations have been practiced all over the world. Although there are some advantages in solo solar thermal power systems, the efficiencies and costs of these systems are not so attractive. Alternately by modifying, if possible, the existing coal-fired power stations to generate green sustainable power, a much more efficient means of power generation can be reached. This paper presents the concept of solar aided power generation in conventional coal-fired power stations, i.e., integrating solar (thermal) energy into conventional fossil fuelled power generation cycles (termed as solar aided thermal power). The solar aided power generation (SAPG) concept has technically been derived to use the strong points of the two technologies (traditional regenerative Rankine cycle with relatively higher efficiency and solar heating at relatively low temperature range). The SAPG does not only contribute to increase the efficiencies of the conventional power station and reduce its emission of the greenhouse gases, but also provides a better way to use solar heat to generate the power. This paper presents the advantages of the SAPG at conceptual level.

  14. Development of a Nuclear Steam Supply System Thermal-Hydraulic Module for the Nuclear Power Plant Simulator Using a Best-Estimate Code, RETRAN

    International Nuclear Information System (INIS)

    Suh, Jae Seung

    2004-08-01

    The NSSS (Nuclear Steam Supply System) thermal-hydraulic programs adopted in the domestic full-scope power plant simulators were provided in early 1980s by foreign vendors. Because of limited computational capability at that time, they usually used very simplified physical models for the real-time simulation of Ness thermal-hydraulic transients, which entails inaccurate results and, thus, the possibility of so-called 'negative training', especially for complicated two-phase flows in the reactor coolant system. To resolve the problem, a realistic NSSS thermal-hydraulic program ARTS has been developed, it was based on the RETRAN code for the improvement of the Nuclear Power Plant full-scope simulator. Since ARTS is a generalized code to solve a simultaneous equation system, the smaller time-step size should be used if converged solution could not obtain even in a single volume. Therefore, dedicated models which do not force to reduce the time-step size are sometimes more suitable in terms of a real-time calculation and robustness. The PRT(Pressurizer Relief Tank) is a good example, which requires a dedicated model. The PRT consists of subcooled water in bottom and non-condensable gas in top. The sparger merged under subcooled water enhances condensation. The complicated thermal-hydraulic phenomena such as condensation, phase separation with existence of non-condensable gas makes difficult to simulate. Therefore, the PRT volume may limit the time-step size if it is modeled with a general control volume. To mitigate the time-step size reduction due to convergence failure at this component using RETRAN, the PRT model was developed as a dedicated model. The dedicated model was expected to provide reasonable results without convergence problem in the analysis of the system transients. The ARTS code guarantees the real-time calculations of almost all transients and ensures the robustness of simulations. However, there are some possibilities of calculation failure in the

  15. Concentrated solar thermal power - Now

    Energy Technology Data Exchange (ETDEWEB)

    Aringhoff, R.; Brakmann, G. [Solar Thermal Power Industry Association ESTIA, Avenue de la Fauconnerie 73, 1170 Brussels (Belgium); Geyer, M. [IEA SolarPACES Implementing Agreement, Avenida de la Paz 51, 04720 Aguadulce, Almeria (Spain); Teske, S. [Greenpeace International, Ottho Heldringstraat 5, 1066 AZ Amsterdam (Netherlands)

    2005-09-15

    This report demonstrates that there are no technical, economic or resource barriers to supplying 5% of the world's electricity needs from solar thermal power by 2040. It is written as practical blueprint to improve understanding of the solar thermal contribution to the world energy supply.

  16. Concentrated solar thermal power - Now

    Energy Technology Data Exchange (ETDEWEB)

    Aringhoff, R.; Brakmann, G. [Solar Thermal Power Industry Association ESTIA, Avenue de la Fauconnerie 73, 1170 Brussels (Belgium); Geyer, M. [IEA SolarPACES Implementing Agreement, Avenida de la Paz 51, 04720 Aguadulce, Almeria (Spain); Teske, S. [Greenpeace International, Ottho Heldringstraat 5, 1066 AZ Amsterdam (Netherlands)

    2005-09-15

    This report demonstrates that there are no technical, economic or resource barriers to supplying 5% of the world's electricity needs from solar thermal power by 2040. It is written as practical blueprint to improve understanding of the solar thermal contribution to the world energy supply.

  17. Improved reliability of power modules

    DEFF Research Database (Denmark)

    Baker, Nick; Liserre, Marco; Dupont, Laurent

    2014-01-01

    Power electronic systems play an increasingly important role in providing high-efficiency power conversion for adjustable-speed drives, power-quality correction, renewable-energy systems, energy-storage systems, and electric vehicles. However, they are often presented with demanding operating...... environments that challenge the reliability aspects of power electronic techniques. For example, increasingly thermally stressful environments are seen in applications such as electric vehicles, where ambient temperatures under the hood exceed 150 °C, while some wind turbine applications can place large...

  18. Nuclear power and other thermal power

    International Nuclear Information System (INIS)

    Bakke, J.

    1978-01-01

    Some philosophical aspects of mortality statistics are first briefly mentioued, then the environmental problems of, first, nuclear power plants, then fossil fuelled power plants are summarised. The effects of releases of carbon dioxide, sulphur dioxide and nitrogen oxides are briefly discussed. The possible health effects of radiation from nuclear power plants and those of gaseous and particulate effluents from fossil fuel plants are also discussed. It is pointed out that in choosing between alternative evils the worst course is to make no choice at all, that is, failure to install thermal power plants will lead to isolated domestic burning of fossil fuels which is clearly the worst situation regarding pollution. (JIW)

  19. Power Electronics Thermal Management | Transportation Research | NREL

    Science.gov (United States)

    Power Electronics Thermal Management Power Electronics Thermal Management A photo of water boiling in liquid cooling lab equipment. Power electronics thermal management research aims to help lower the investigates and develops thermal management strategies for power electronics systems that use wide-bandgap

  20. Concentration solar thermal power

    International Nuclear Information System (INIS)

    Livet, F.

    2011-01-01

    As the production of electricity by concentration solar power (CSP) installations is said to be a source of energy for the future, the author discusses past experiments (notably the French Thermis project), and the different techniques which are currently being used. He indicates the regions which appear to be the most appropriate for this technique. He presents the three main techniques: parabolic cylinder, tower, and Stirling cycle installations. He discusses the issue of intermittency. He proposes an assessment of prices and of their evolution, and indicates the investments made in different installations (in Italy, Spain, Germany and Portugal). He comments the case of hybrid installations (sun and gas), evokes the Desertec project proposed by the German industry which comprises a set of hybrid installations. He notices that there is no significant technological evolution for this process

  1. Solar thermal energy conversion to electrical power

    International Nuclear Information System (INIS)

    Trinh, Anh-Khoi; González, Ivan; Fournier, Luc; Pelletier, Rémi; Sandoval V, Juan C.; Lesage, Frédéric J.

    2014-01-01

    The conversion of solar energy to electricity currently relies primarily on the photovoltaic effect in which photon bombardment of photovoltaic cells drives an electromotive force within the material. Alternatively, recent studies have investigated the potential of converting solar radiation to electricity by way of the Seebeck effect in which charge carrier mobility is generated by an asymmetric thermal differential. The present study builds upon these latest advancements in the state-of-the-art of thermoelectric system management by combining solar evacuated tube technology with commercially available Bismuth Telluride semiconductor modules. The target heat source is solar radiation and the target heat sink is thermal convection into the ambient air relying on wind aided forced convection. These sources of energy are reproduced in a laboratory controlled environment in order to maintain a thermal dipole across a thermoelectric module. The apparatus is then tested in a natural environment. The novelty of the present work lies in a net thermoelectric power gain for ambient environment applications and an experimental validation of theoretical electrical characteristics relative to a varying electrical load. - Highlights: • Solar radiation maintains a thermal tension which drives an electromotive force. • Voltage, current and electric power are reported and discussed. • Theoretical optimal thermoelectric conversion predictions are presented. • Theory is validated with experimentally measured data

  2. Serial powering of pixel modules

    International Nuclear Information System (INIS)

    Stockmanns, Tobias; Fischer, Peter; Huegging, Fabian; Peric, Ivan; Runolfsson, O.; Wermes, Norbert

    2003-01-01

    Modern pixel detectors for the next generation of high-energy collider experiments like LHC use readout electronics in deep sub-micron technology. Chips in this technology need a low supply voltage of 2-2.5 V alongside high current consumption to achieve the desired performance. The high supply current leads to significant voltage drops in the long and low mass supply cables so that voltage fluctuations at the chips are induced, when the supply current changes. This problem scales with the number of modules when connected in parallel to the power supplies. An alternative powering scheme connects several modules in series resulting in a higher supply voltage but a lower current consumption of the chain and therefore a much lower voltage drop in the cables. In addition the amount of cables needed to supply the detector is vastly reduced. The concept and features of serial powering are presented and studies of the implementation of this technology as an alternative for the ATLAS pixel detector are shown. In particular, it is shown that the potential risk of powering in series can be addressed and eliminated

  3. Application of Thermal Network Model to Transient Thermal Analysis of Power Electronic Package Substrate

    Directory of Open Access Journals (Sweden)

    Masaru Ishizuka

    2011-01-01

    Full Text Available In recent years, there is a growing demand to have smaller and lighter electronic circuits which have greater complexity, multifunctionality, and reliability. High-density multichip packaging technology has been used in order to meet these requirements. The higher the density scale is, the larger the power dissipation per unit area becomes. Therefore, in the designing process, it has become very important to carry out the thermal analysis. However, the heat transport model in multichip modules is very complex, and its treatment is tedious and time consuming. This paper describes an application of the thermal network method to the transient thermal analysis of multichip modules and proposes a simple model for the thermal analysis of multichip modules as a preliminary thermal design tool. On the basis of the result of transient thermal analysis, the validity of the thermal network method and the simple thermal analysis model is confirmed.

  4. Nonreciprocal Thermal Material by Spatiotemporal Modulation

    Science.gov (United States)

    Torrent, Daniel; Poncelet, Olivier; Batsale, Jean-Chirstophe

    2018-03-01

    The thermal properties of a material with a spatiotemporal modulation, in the form of a traveling wave, in both the thermal conductivity and the specific heat capacity are studied. It is found that these materials behave as materials with an internal convectionlike term that provides them with nonreciprocal properties, in the sense that the heat flux has different properties when it propagates in the same direction or in the opposite one to the modulation of the parameters. An effective medium description is presented which accurately describes the modulated material, and numerical simulations support this description and verify the nonreciprocal properties of the material. It is found that these materials are promising candidates for the design of thermal diodes and other advanced devices for the control of the heat flow at all scales.

  5. Thermal Module Tests with Irradiated 070 Detectors.

    CERN Document Server

    HOWCROFT, C L F

    1998-01-01

    Four n-in-n detectors were irradiated at KEK to a fluence of 3*1014 protons cm-2. These were used to construct a thermal barrel module to 070 drawings with an A3-90 baseboard at the Rutherford Appleton Laboratory. Thermal testes were conducted on the module, examining the runaway point and the temperatures across the silicon. The results obtained were used to calculate the runaway point under ATLAS conditions. It was concluded that this module meets the specifications in the Technical Design Report, of 160 mW mm-2@ 0°C for runaway and less than 5°C across the silicon. The module was also compared to a Finite Element Analysis, and showed a good agreement.

  6. Serial powering of pixel modules

    CERN Document Server

    Stockmanns, Tobias; Hügging, Fabian Georg; Peric, I; Runólfsson, O; Wermes, Norbert

    2003-01-01

    Modern pixel detectors for the next generation of high-energy collider experiments like LHC use readout electronics in deep sub- micron technology. Chips in this technology need a low supply voltage of 2-2.5 V alongside high current consumption to achieve the desired performance. The high supply current leads to significant voltage drops in the long and low mass supply cables so that voltage fluctuations at the chips are induced, when the supply current changes. This problem scales with the number of modules when connected in parallel to the power supplies. An alternative powering scheme connects several modules in series resulting in a higher supply voltage but a lower current consumption of the chain and therefore a much lower voltage drop in the cables. In addition the amount of cables needed to supply the detector is vastly reduced. The concept and features of serial powering are presented and studies of the implementation of this technology as an alternative for the ATLAS pixel detector are shown. In par...

  7. Continuous hydrino thermal power system

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Randell L.; Zhao, Guibing; Good, William [BlackLight Power, Inc., 493 Old Trenton Road, Cranbury, NJ 08512 (United States)

    2011-03-15

    The specifics of a continuous hydrino reaction system design are presented. Heat from the hydrino reactions within individual cells provide both reactor power and the heat for regeneration of the reactants. These processes occur continuously and the power from each cell is constant. The conversion of thermal power to electrical power requires the use of a heat engine exploiting a cycle such as a Rankine, Brayton, Stirling, or steam-engine cycle. Due to the temperatures, economy goal, and efficiency, the Rankine cycle is the most practical and can produce electricity at 30-40% efficiency with a component capital cost of about $300 per kW electric. Conservatively, assuming a conversion efficiency of 25% the total cost with the addition of the boiler and chemical components is estimated at $1064 per kW electric. (author)

  8. Continuous hydrino thermal power system

    International Nuclear Information System (INIS)

    Mills, Randell L.; Zhao, Guibing; Good, William

    2011-01-01

    The specifics of a continuous hydrino reaction system design are presented. Heat from the hydrino reactions within individual cells provide both reactor power and the heat for regeneration of the reactants. These processes occur continuously and the power from each cell is constant. The conversion of thermal power to electrical power requires the use of a heat engine exploiting a cycle such as a Rankine, Brayton, Stirling, or steam-engine cycle. Due to the temperatures, economy goal, and efficiency, the Rankine cycle is the most practical and can produce electricity at 30-40% efficiency with a component capital cost of about $300 per kW electric. Conservatively, assuming a conversion efficiency of 25% the total cost with the addition of the boiler and chemical components is estimated at $1064 per kW electric.

  9. Thermal effects in microfluidics with thermal conductivity spatially modulated

    Science.gov (United States)

    Vargas Toro, Agustín.

    2014-05-01

    A heat transfer model on a microfluidic is resolved analytically. The model describes a fluid at rest between two parallel plates where each plate is maintained at a differentially specified temperature and the thermal conductivity of the microfluidic is spatially modulated. The heat transfer model in such micro-hydrostatic configuration is analytically resolved using the technique of the Laplace transform applying the Bromwich Integral and the Residue theorem. The temperature outline in the microfluidic is presented as an infinite series of Bessel functions. It is shown that the result for the thermal conductivity spatially modulated has as a particular case the solution when the thermal conductivity is spatially constant. All computations were performed using the computer algebra software Maple. It is claimed that the analytical obtained results are important for the design of nanoscale devices with applications in biotechnology. Furthermore, it is suggested some future research lines such as the study of the heat transfer model in a microfluidic resting between coaxial cylinders with radially modulated thermal conductivity in order to achieve future developments in this area.

  10. Solar thermal power meeting - Proceedings

    International Nuclear Information System (INIS)

    2011-07-01

    This document summarizes the presentations and debates of the first edition of the Solar thermal power meeting. Content: 1 - Opening talk (Jean-Louis BAL, SER); 2 - Solar thermal power, European and global road-maps (Cedric Philibert, IEA; Mariangels Perez Latorre, Estela); 3 - first round-table on the international development of solar energy (Philippe Lorec, DGEC France; Said Mouline, Aderee Morocco; Obaid Amrane, Masen Morocco; Kawther Lihidheb, ANME Tunisia; Abdelaziz Boumahra, Rouiba Eclairage, Algeria; Badis Derradji, NEAL Algeria; Yao Azoumah, Lesee, 2IE Foundation Burkina Faso; Mamadou Amadou Kane, MPEM Mauritania; Jean-Charles Mulet, Bertin Technologies); 4 - Second round-table on the French solar thermal offer for export (Georgina Grenon, DGEC; Stephanie Bouzigueseschmann, DG Tresor; Armand Pineda, Alstom; Florent Brunet, Mena-Areva; Roger Pujol, CNIM; Gilles David, Enertime; Michel Wohrer, Saed; Mathieu Vrinat, Sogreah; Marc Benmarraze, Solar Euromed; 5 - Presentation of Amisole - Moroccan association of solar and wind industries (Ahmed Squalli, Amisole); 6 - Third round-table on French research at the solar industry service (Gilles Flamant, Promes Lab. CNRS; Francois Moisan, Ademe; Tahar Melliti, CGI; Andre Joffre, Derbi; Michel Wohrer, Capenergies; 7 - Fourth round table on projects financing (Vincent Girard, Loan Officer BEI; Bertrand Marchais, Miga World Bank; Philippe Meunier, CDC Climat Groupe Caisse des Depots; Christian de Gromard, AFD; Laurent Belouze, Natixis; Piotr Michalowski, Loan Officer BEI); 8 - Closing of the meeting (Roger Pujol, SER)

  11. Thermal performance measurements on ATLAS-SCT KB forward modules

    CERN Document Server

    Donegà, M; D'Onofrio, M; Ferrère, D; Hirt, C; Ikegami, Y; Kohriki, T; Kondo, T; Lindsay, S; Mangin-Brinet, M; Niinikoski, T O; Pernegger, H; Perrin, E; Taylor, G; Terada, S; Unno, Y; Wallny, R; Weber, M

    2003-01-01

    The thermal design of the KB module is presented. A Finite Elements Analysis (FEA) has been used to finalize the module design. The thermal performance of an outer irradiated KB module has been measured at different cooling conditions. The thermal runaway of the module has been measured. The FEA model has been compared with the measurements and has been used to predict the thermal performance in a realistic SCT scenario.

  12. Thermal power plant design and operation

    CERN Document Server

    Sarkar, Dipak

    2015-01-01

    Thermal Power Plant: Design and Operation deals with various aspects of a thermal power plant, providing a new dimension to the subject, with focus on operating practices and troubleshooting, as well as technology and design. Its author has a 40-long association with thermal power plants in design as well as field engineering, sharing his experience with professional engineers under various training capacities, such as training programs for graduate engineers and operating personnel. Thermal Power Plant presents practical content on coal-, gas-, oil-, peat- and biomass-fueled thermal power

  13. Spark Plasma Sintering constrained process parameters of sintered silver paste for connection in power electronic modules: Microstructure, mechanical and thermal properties

    Energy Technology Data Exchange (ETDEWEB)

    Alayli, N. [Université Paris 13, Sorbonne Paris Cité, Laboratoire des Sciences des Procédés et des Matériaux, Centre National de la Recherche Scientifique, Unité Propre de Recherche 3407, 99 avenue Jean Baptiste Clément, F-93430 Villetaneuse (France); Université de Versailles-Saint-Quentin-en-Yvelines, Sorbonne Universités, Université Pierre et Marie Curie, Université Paris 06, Centre National de la Recherche Scientifique/INSU, Laboratoire Atmosphères Milieux Observations Spatiales-IPSL, Quartier des Garennes, 11 Boulevard d' Alembert, F-78280 Guyancourt (France); Schoenstein, F., E-mail: frederic.schoenstein@univ-paris13.fr [Université Paris 13, Sorbonne Paris Cité, Laboratoire des Sciences des Procédés et des Matériaux, Centre National de la Recherche Scientifique, Unité Propre de Recherche 3407, 99 avenue Jean Baptiste Clément, F-93430 Villetaneuse (France); Girard, A. [Office National d' Étude et de Recherches Aérospatiales, Laboratoire d' Étude des Microstructures, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 104, 29 avenue de la Division Leclerc, F-92322 Châtillon (France); and others

    2014-11-14

    Processing parameters of Spark Plasma Sintering (SPS) technique were constrained to process nano sized silver particles bound in a paste for interconnection in power electronic devices. A novel strategy combining debinding step and consolidation processes (SPS) in order to elaborate nano-structured silver bulk material is investigated. Optimum parameters were sought for industrial power electronics packaging from the microstructural and morphological properties of the sintered material. The latter was studied by Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) to determine the density and the grain size of crystallites. Two types of samples, termed S1 (bulk) and S2 (multilayer) were elaborated and characterized. They are homogeneous with a low degree of porosity and a good adhesion to the substrate and the process parameters are compatible with industrial constraints. As the experimental results show, the mean crystallite size is between 60 nm and 790 nm with a density between 50% and 92% resulting in mechanical and thermal properties that are better than that of lead free solder. The best SPS sintering parameters, the applied pressure, the temperature and the processing time were determined as being 3 MPa, 300 °C and 1 min respectively when the desizing time of the preprocessing step was kept below 5 min at 150 °C. Using these processing parameters, acceptable for automotive packaging industry, a semi-conductor power chip was successfully connected to a metalized substrate by sintered silver with thermal and electrical properties better than those of current solders and with thermomechanical properties allowing absorption of thermoplastic stresses. - Highlights: • The sintered silver joints have nanometric structure. • The grain growth was controlled by the SPS sintering parameters. • New connection material improve thermal and electrical properties of current solders. • Interconnection's plastic strain can absorb thermo

  14. Thermoelectric power generator for variable thermal power source

    Science.gov (United States)

    Bell, Lon E; Crane, Douglas Todd

    2015-04-14

    Traditional power generation systems using thermoelectric power generators are designed to operate most efficiently for a single operating condition. The present invention provides a power generation system in which the characteristics of the thermoelectrics, the flow of the thermal power, and the operational characteristics of the power generator are monitored and controlled such that higher operation efficiencies and/or higher output powers can be maintained with variably thermal power input. Such a system is particularly beneficial in variable thermal power source systems, such as recovering power from the waste heat generated in the exhaust of combustion engines.

  15. Triple Pulse Tester - Efficient Power Loss Characterization of Power Modules

    DEFF Research Database (Denmark)

    Trintis, Ionut; Poulsen, Thomas; Beczkowski, Szymon

    2015-01-01

    In this paper the triple pulse testing method and circuit for power loss characterization of power modules is introduced. The proposed test platform is able to accurately characterize both the switching and conduction losses of power modules in a single automated process. A configuration of a half...

  16. Thermal Power Plant Performance Analysis

    CERN Document Server

    2012-01-01

    The analysis of the reliability and availability of power plants is frequently based on simple indexes that do not take into account the criticality of some failures used for availability analysis. This criticality should be evaluated based on concepts of reliability which consider the effect of a component failure on the performance of the entire plant. System reliability analysis tools provide a root-cause analysis leading to the improvement of the plant maintenance plan.   Taking in view that the power plant performance can be evaluated not only based on  thermodynamic related indexes, such as heat-rate, Thermal Power Plant Performance Analysis focuses on the presentation of reliability-based tools used to define performance of complex systems and introduces the basic concepts of reliability, maintainability and risk analysis aiming at their application as tools for power plant performance improvement, including: ·         selection of critical equipment and components, ·         defini...

  17. Power Loss Calculation and Thermal Modelling for a Three Phase Inverter Drive System

    Directory of Open Access Journals (Sweden)

    Z. Zhou

    2005-12-01

    Full Text Available Power losses calculation and thermal modelling for a three-phase inverter power system is presented in this paper. Aiming a long real time thermal simulation, an accurate average power losses calculation based on PWM reconstruction technique is proposed. For carrying out the thermal simulation, a compact thermal model for a three-phase inverter power module is built. The thermal interference of adjacent heat sources is analysed using 3D thermal simulation. The proposed model can provide accurate power losses with a large simulation time-step and suitable for a long real time thermal simulation for a three phase inverter drive system for hybrid vehicle applications.

  18. Thermal management of solid state lighting module

    NARCIS (Netherlands)

    Ye, H.

    2014-01-01

    Solid-State Lighting (SSL), powered by Light-Emitting Diodes (LEDs), is an energy-efficient technology for lighting systems. In contrast to incandescent lights which obtain high efficiency at high temperatures, the highest efficiency of LEDs is reached at low temperatures. The thermal management in

  19. Thermal management, systems and modules; Thermomanagement, Systeme und Module

    Energy Technology Data Exchange (ETDEWEB)

    Flik, M. [Behr GmbH und Co., Stuttgart (Germany)

    1999-11-01

    Up till now the individual systems for engine temperature control and air conditioning of the vehicle cabin have to a large extent been viewed independently of one another. With the progress of electronic control systems, however, Behr has adopted an integrative approach to managing all heat and substance flows outside of the engine. This perspective, which is known as thermal management, has significantly boosted the rate of innovation. In a short period of time, new and optimized modules and systems have allowed considerable improvements to be made in relation to passenger comfort and safety, the integration of subsystems and modules into the vehicle and environmental compatibility. This innovation drive, which also extends to the design of major modules, will continue to gain impetus in the future. (orig.) [German] Bisher wurden die verschiedenen Systeme zur Temperierung des Motors und zur Klimatisierung der Fahrzeugkabine weitgehend unabhaengig voneinander betrachtet. Mit dem Vordringen der elektronischen Regelung hat bei Behr jedoch eine gesamtheitliche Betrachtung aller Waerme- und Stoffstroeme ausserhalb des Motors eingesetzt. Diese Sichtweise, Thermomanagement genannt, hat eine erhebliche Innovationsdynamik ermoeglicht. Mit neuen und optimierten Modulen und Systemen konnten in kurzer Zeit betraechtliche Verbesserungen erzielt werden - bei Komfort und Sicherheit der Fahrzeuginsassen, bei der Integration der Subsysteme und Module ins Fahrzeug sowie bei seiner oekologischen Vertraeglichkeit. Diese Innovationsdynamik, die auch die Bildung von Grossmodulen einschliesst, wird in Zukunft noch zunehmen. (orig.)

  20. Thermally modulated biomolecule transport through nanoconfined channels.

    Science.gov (United States)

    Liu, Lei; Zhu, Lizhong

    2015-01-01

    In this work, a nanofluidic device containing both a feed cell and a permeation cell linked by nanopore arrays has been fabricated, which is employed to investigate thermally controlled biomolecular transporting properties through confined nanochannels. The ionic currents modulated by the translocations of goat antibody to human immunoglobulin G (IgG) or bovine serum albumin (BSA) are recorded and analyzed. The results suggest that the modulation effect decreases with the electrolyte concentration increasing, while the effects generated by IgG translocation are more significant than that generated by BSA translocation. More importantly, there is a maximum decreasing value in each modulated current curve with biomolecule concentration increasing for thermally induced intermolecular collision. Furthermore, the turning point for the maximum shifts to lower biomolecule concentrations with the system temperature rising (from 4°C to 45°C), and it is mainly determined by the temperature in the feed cell if the temperature difference exists in the two separated cells. These findings are expected to be valuable for the future design of novel sensing device based on nanopore and/or nanopore arrays.

  1. Innovative use of power integrated modules for DC power supplies

    DEFF Research Database (Denmark)

    Ørndrup Nielsen, Rasmus; Elkiær, Alexander; Munk-Nielsen, Stig

    2013-01-01

    In this article several innovative ways of utilizing Power Integrated Modules (PIM) as switching device in a DC power supply are presented. PIM have advantages in compactness of design, cost and fast prototype due to easier PCB layout. A PIM converter topology is chosen and designed resulting...... in an experimental setup. Results from the setup are presented showing the feasibility of using a PIM module as almost all power semiconductors in a DC power supply....

  2. Thermal and optical performance of encapsulation systems for flat-plate photovoltaic modules

    Science.gov (United States)

    Minning, C. P.; Coakley, J. F.; Perrygo, C. M.; Garcia, A., III; Cuddihy, E. F.

    1981-01-01

    The electrical power output from a photovoltaic module is strongly influenced by the thermal and optical characteristics of the module encapsulation system. Described are the methodology and computer model for performing fast and accurate thermal and optical evaluations of different encapsulation systems. The computer model is used to evaluate cell temperature, solar energy transmittance through the encapsulation system, and electric power output for operation in a terrestrial environment. Extensive results are presented for both superstrate-module and substrate-module design schemes which include different types of silicon cell materials, pottants, and antireflection coatings.

  3. Power Electronics Thermal Management R&D (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Waye, S.

    2014-11-01

    This project will investigate and develop thermal-management strategies for wide bandgap (WBG)-based power electronics systems. Research will be carried out to deal with thermal aspects at the module- and system-level. Module-level research will focus on die- and substrate-integrated cooling strategies and heat-transfer enhancement technologies. System-level research will focus on thermal-management strategies for the entire power electronics system to enable smart packaging solutions. One challenge with WBG device-based power electronics is that although losses in the form of heat may be lower, the footprint of the components is also likely to be reduced to reduce cost, weight, and volume. Combined with higher operational temperatures, this creates higher heat fluxes which much be removed from a smaller footprint, requiring advanced cooling strategies.

  4. Cooling towers for thermal power plants

    International Nuclear Information System (INIS)

    Chaboseau, J.

    1987-01-01

    After a brief recall on cooling towers testing and construction, this paper presents four examples of very large French nuclear power plant cooling towers, and one of an Australian thermal power plant [fr

  5. Thermal Impact Analysis of Circulating Current in High Power Modular Online Uninterruptible Power Supplies Application

    DEFF Research Database (Denmark)

    Zhang, Chi; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2017-01-01

    In modular uninterruptible power supplies (UPSs), several DC/AC modules are required to work in parallel. This structure allows the system to be more reliable and flexible. These DC/AC modules share the same DC bus and AC critical bus. Module differences, such as filter inductor, filter capacitor......, control parameters, and so on, will make it possible for the potential zero sequence current to flow among the modules. This undesired type of circulating current will bring extra losses to the power semiconductor devices in the system, which should be paid special attention in high power application...... scenarios. In this paper, plug’n’play modules and cycle control are discussed and validated through experimental results. Moreover, potential zero sequence circulating current impact on power semiconductor devices thermal performance is also analyzed in this paper....

  6. Power Electronics Thermal Management R&D: Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilbert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-04-08

    The objective for this project is to develop thermal management strategies to enable efficient and high-temperature wide-bandgap (WBG)-based power electronic systems (e.g., emerging inverter and DC-DC converter). Device- and system-level thermal analyses are conducted to determine the thermal limitations of current automotive power modules under elevated device temperature conditions. Additionally, novel cooling concepts and material selection will be evaluated to enable high-temperature silicon and WBG devices in power electronics components. WBG devices (silicon carbide [SiC], gallium nitride [GaN]) promise to increase efficiency, but will be driven as hard as possible. This creates challenges for thermal management and reliability.

  7. Apparatus and method for thermal power generation

    International Nuclear Information System (INIS)

    Cohen, P.; Redding, A.H.

    1978-01-01

    An improved thermal power plant and method of power generation is described which minimizes thermal stress and chemical impurity buildup in the vaporizing component, particularly beneficial under loss of normal feed fluid and startup conditions. The invention is particularly applicable to a liquid metal fast breeder reactor plant

  8. Solar energy thermally powered electrical generating system

    Science.gov (United States)

    Owens, William R. (Inventor)

    1989-01-01

    A thermally powered electrical generating system for use in a space vehicle is disclosed. The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat. A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse. The control system is based upon Kalman filter theory.

  9. KMRR thermal power measurement error estimation

    International Nuclear Information System (INIS)

    Rhee, B.W.; Sim, B.S.; Lim, I.C.; Oh, S.K.

    1990-01-01

    The thermal power measurement error of the Korea Multi-purpose Research Reactor has been estimated by a statistical Monte Carlo method, and compared with those obtained by the other methods including deterministic and statistical approaches. The results show that the specified thermal power measurement error of 5% cannot be achieved if the commercial RTDs are used to measure the coolant temperatures of the secondary cooling system and the error can be reduced below the requirement if the commercial RTDs are replaced by the precision RTDs. The possible range of the thermal power control operation has been identified to be from 100% to 20% of full power

  10. Power transistor module for high current applications

    International Nuclear Information System (INIS)

    Cilyo, F.F.

    1975-01-01

    One of the parts needed for the control system of the 400-GeV accelerator at Fermilab was a power transistor with a safe operating area of 1800A at 50V, dc current gain of 100,000 and 20 kHz bandwidth. Since the commercially available discrete devices and power hybrid packages did not meet these requirements, a power transistor module was developed which performed satisfactorily. By connecting 13 power transistors in parallel, with due consideration for network and heat dissipation problems, and by driving these 13 with another power transistor, a super power transistor is made, having an equivalent current, power, and safe operating area capability of 13 transistors. For higher capabilities, additional modules can be conveniently added. (auth)

  11. Water pollution and thermal power stations

    International Nuclear Information System (INIS)

    Maini, A.; Harapanahalli, A.B.

    1993-01-01

    There are a number of thermal power stations dotting the countryside in India for the generation of electricity. The pollution of environment is continuously increasing in the country with the addition of new coal based power stations and causing both a menace and a hazard to the biota. The paper reviews the problems arising out of water pollution from the coal based thermal power stations. (author). 2 tabs

  12. A learning curve for solar thermal power

    Science.gov (United States)

    Platzer, Werner J.; Dinter, Frank

    2016-05-01

    Photovoltaics started its success story by predicting the cost degression depending on cumulated installed capacity. This so-called learning curve was published and used for predictions for PV modules first, then predictions of system cost decrease also were developed. This approach is less sensitive to political decisions and changing market situations than predictions on the time axis. Cost degression due to innovation, use of scaling effects, improved project management, standardised procedures including the search for better sites and optimization of project size are learning effects which can only be utilised when projects are developed. Therefore a presentation of CAPEX versus cumulated installed capacity is proposed in order to show the possible future advancement of the technology to politics and market. However from a wide range of publications on cost for CSP it is difficult to derive a learning curve. A logical cost structure for direct and indirect capital expenditure is needed as the basis for further analysis. Using derived reference cost for typical power plant configurations predictions of future cost have been derived. Only on the basis of that cost structure and the learning curve levelised cost of electricity for solar thermal power plants should be calculated for individual projects with different capacity factors in various locations.

  13. Thermal Aspects Related to Power Assemblies

    Directory of Open Access Journals (Sweden)

    PLESCA, A.

    2010-02-01

    Full Text Available In many cases when a power assembly based on power semiconductors is used, catastrophic failure is the result of steep temperature gradient in the localized temperature distribution. Hence, an optimal heatsink design for certain industrial applications has become a real necessity. In this paper, the Pro/ENGINEER software with the thermal simulation integrated tool, Pro/MECHANICA, has been used for thermal study of a specific power semiconductor assembly. A series of steady-state and transient thermal simulations have been performed. The experimental tests have confirmed the simulation results. Therefore, the use of specific 3D modeling and simulation software allows to design special power semiconductor assemblies with a better thermal transfer between its heatsink and power electronic components at given operating conditions.

  14. Thermal power plant efficiency enhancement with Ocean Thermal Energy Conversion

    International Nuclear Information System (INIS)

    Soto, Rodrigo; Vergara, Julio

    2014-01-01

    In addition to greenhouse gas emissions, coastal thermal power plants would gain further opposition due to their heat rejection distressing the local ecosystem. Therefore, these plants need to enhance their thermal efficiency while reducing their environmental offense. In this study, a hybrid plant based on the principle of Ocean Thermal Energy Conversion was coupled to a 740 MW coal-fired power plant project located at latitude 28°S where the surface to deepwater temperature difference would not suffice for regular OTEC plants. This paper presents the thermodynamical model to assess the overall efficiency gained by adopting an ammonia Rankine cycle plus a desalinating unit, heated by the power plant condenser discharge and refrigerated by cold deep seawater. The simulation allowed us to optimize a system that would finally enhance the plant power output by 25–37 MW, depending on the season, without added emissions while reducing dramatically the water temperature at discharge and also desalinating up to 5.8 million tons per year. The supplemental equipment was sized and the specific emissions reduction was estimated. We believe that this approach would improve the acceptability of thermal and nuclear power plant projects regardless of the plant location. -- Highlights: • An Ocean Thermal Energy Conversion hybrid plant was designed. • The waste heat of a power plant was delivered as an OTEC heat source. • The effect of size and operating conditions on plant efficiency were studied. • The OTEC implementation in a Chilean thermal power plant was evaluated. • The net efficiency of the thermal power plant was increased by 1.3%

  15. Three frequency modulated combination thermal neutron lifetime log and porosity

    International Nuclear Information System (INIS)

    Paap, H.J.; Arnold, D.M.; Smith, M.P.

    1976-01-01

    Methods are disclosed for measuring simultaneously the thermal neutron lifetime of the borehole fluid and earth formations in the vicinity of a well borehole, together with the formation porosity. A harmonically intensity modulated source of fast neutrons is used to irradiate the earth formations with fast neutrons at three different modulation frequencies. Intensity modulated clouds of thermal neutrons at each of the three modulation frequencies are detected by dual spaced detectors and the relative phase shift of the thermal neutrons with respect to the fast neutrons is determined at each of the three modulation frequencies at each detector. These measurements are then combined to determine simultaneously the thermal neutron decay time of the borehole fluid, the thermal neutron decay time of surrounding earth formation media and the porosity of the formation media

  16. Nuclear Power Plant Module, NPP-1: Nuclear Power Cost Analysis.

    Science.gov (United States)

    Whitelaw, Robert L.

    The purpose of the Nuclear Power Plant Modules, NPP-1, is to determine the total cost of electricity from a nuclear power plant in terms of all the components contributing to cost. The plan of analysis is in five parts: (1) general formulation of the cost equation; (2) capital cost and fixed charges thereon; (3) operational cost for labor,…

  17. Strategies for growth of thermal power

    International Nuclear Information System (INIS)

    Shah, R.K.D.

    1998-01-01

    The power generating industry in India is at the cross roads. Massive investments are required to achieve GDP growth of 7-8% per annum over the next 10 years. For this, appropriate strategies have to be evolved which will give the country best returns. With coal being the major fuel resource in India, thermal power generation will continue to be the mainstay in the next decade. This paper covers various key issues to be addressed covering the plan and perspectives of thermal power, environmental issues, technology strategies for growth, power policy and R and D. (author)

  18. An inherently safe power reactor module

    International Nuclear Information System (INIS)

    Salerno, L.N.

    1985-01-01

    General Electric's long participation in liquid metal reactor technology has led to a Power Reactor Inherently Safe Module (PRISM) concept supported by DOE contract DE-AC06-85NE37937. The reactor module is sized to maximize inherent safety features. The small size allows factory fabrication, reducing field construction and field QA/QC labor, and allows safety to be demonstrated in full scale, to support a pre-licensed standard commercial product. The module is small enough to be placed underground, and can be combined with steam and electrical generating equipment to provide a complete electrical power producing plant in the range of 400-1200 MWe. Initial assessments are that the concept has the potential to be economically competitive with existing methods of power production used by the utility industry

  19. Radio frequency powering of microelectronic sensor modules

    Energy Technology Data Exchange (ETDEWEB)

    Boegel, Gerd vom; Meyer, Frederic; Kemmerling, Martin [Fraunhofer-Institut fuer Mikroelektronische Schaltungen und Systeme, Duisburg (Germany)

    2013-03-01

    In RFID applications the power supply of transponders via electromagnetic field is state-of-the-art. In this presentation the use of electromagnetic energy will be discussed for the operation of sensor modules. Starting with the question, whether the omnipresent radiation from power supply networks, radio transmitters, and mobile phone base stations is useable (energy harvesting), the feasibility of the operation of self-sufficient sensor modules is explained. Ancillary conditions of typical applications (e.g. operating range) and technology are considered. (orig.)

  20. Financing Solar Thermal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kistner, Rainer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Price, Henry W. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    1999-04-14

    The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been build following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply stated, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised in debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects from the financier’s perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies.

  1. Financing Solar Thermal Power Plants

    International Nuclear Information System (INIS)

    Price, Henry W.; Kistner, Rainer

    1999-01-01

    The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been build following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply stated, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised in debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects from the financier's perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies

  2. Financing solar thermal power plants

    International Nuclear Information System (INIS)

    Kistner, R.; Price, H.

    1999-01-01

    The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been built following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply states, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised in debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects form the financier's perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies

  3. Joint excitation and reactive power control in thermal power plant

    Directory of Open Access Journals (Sweden)

    Dragosavac Jasna

    2013-01-01

    Full Text Available The coordinated voltage and reactive power controller, designed for the thermal power plant, is presented in the paper. A brief explanation of the need for such device is given and justification for commissioning of such equipment is outlined. After short description of the theoretical background of the proposed control design, the achieved features of the commissioned equipment are fully given. Achieved performances are illustrated by recorded reactive power and bus voltage responses after commissioning of the described equipment into the largest thermal power plant in Serbia. As it can be seen in presented records, all design targets are met.

  4. Tasks of a power engineer in future thermal power plants

    International Nuclear Information System (INIS)

    Freymeyer, P.; Scherschmidt, F.

    1982-01-01

    Today already the power plants provide plenty of tasks and problems to the electrical engineer in the fields of power and conductive engineering. A completely new orientation of power engineering leads to larger, more complex system and even to systems unknown so far. In conductive engineering entirely new solutions have come in view. There are a lot of interesting topics for the electrical engineer in the rearrangement and advance into virgin territory of thermal power plants. (orig.) [de

  5. thermal power stations' reliability evaluation in a hydrothermal system

    African Journals Online (AJOL)

    Dr Obe

    A quantitative tool for the evaluation of thermal power stations reliability in a hydrothermal system is presented. ... (solar power); wind (wind power) and the rest, thermal power and ... probability of a system performing its function adequately for ...

  6. Thermal power plants and environment

    International Nuclear Information System (INIS)

    1997-01-01

    Recent versions of the air quality models which are reviewed and approved from the Environmental Protection Agency (EPA) are analysed in favour of their application in simple and complex terrain, different meteorological conditions and modifications in the sources of pollutant emissions. Improvement of the standard methods for analysis of the risks affecting the environment from different energy sources has been carried out. The application of the newly introduced model enabled (lead to performing) risk analysis of the coal power plants compared to other types of energy sources. Detailed investigation of the risk assessment and perception from coal power plants, has been performed and applied to the Macedonian coal power plants. Introducing the concept of 'psychological pollution', a modification of the standard models and programs for risk assessment from various energy sources has been suggested (proposed). The model has been applied to REK Bitola, where statistically relevant differences in relation to the control groups have been obtained. (Original)

  7. Simbol-X Mirror Module Thermal Shields: II-Small Angle X-Ray Scattering Measurements

    Science.gov (United States)

    Barbera, M.; Ayers, T.; Collura, A.; Nasillo, G.; Pareschi, G.; Tagliaferri, G.

    2009-05-01

    The formation flight configuration of the Simbol-X mission implies that the X-ray mirror module will be open to Space on both ends. In order to reduce the power required to maintain the thermal stability and, therefore, the high angular resolution of the shell optics, a thin foil thermal shield will cover the mirror module. Different options are presently being studied for the foil material of these shields. We report results of an experimental investigation conducted to verify that the scattering of X-rays, by interaction with the thin foil material of the thermal shield, will not significantly affect the performances of the telescope.

  8. Simbol-X Mirror Module Thermal Shields: II-Small Angle X-Ray Scattering Measurements

    International Nuclear Information System (INIS)

    Barbera, M.; Ayers, T.; Collura, A.; Nasillo, G.; Pareschi, G.; Tagliaferri, G.

    2009-01-01

    The formation flight configuration of the Simbol-X mission implies that the X-ray mirror module will be open to Space on both ends. In order to reduce the power required to maintain the thermal stability and, therefore, the high angular resolution of the shell optics, a thin foil thermal shield will cover the mirror module. Different options are presently being studied for the foil material of these shields. We report results of an experimental investigation conducted to verify that the scattering of X-rays, by interaction with the thin foil material of the thermal shield, will not significantly affect the performances of the telescope.

  9. Virginia Power thermal-hydraulics methods

    International Nuclear Information System (INIS)

    Anderson, R.C.; Basehore, K.L.; Harrell, J.R.

    1987-01-01

    Virginia Power's nuclear safety analysis group is responsible for the safety analysis of reload cores for the Surry and North Anna power stations, including the area of core thermal-hydraulics. Postulated accidents are evaluated for potential departure from nucleate boiling violations. In support of these tasks, Virginia Power has employed the COBRA code and the W-3 and WRB-1 DNB correlations. A statistical DNBR methodology has also been developed. The code, correlations and statistical methodology are discussed

  10. Effect of Asymmetric Layout of IGBT Modules on Reliability of Power Inverters in Motor Drive System

    DEFF Research Database (Denmark)

    Choi, Uimin; Vernica, Ionut; Blaabjerg, Frede

    2018-01-01

    of inverters are limited by the most stressed devices. However, generally common data is provided for all devices and this may cause improper design of the inverters in terms of power rating and lifetime. In this paper, the effect of an asymmetric layout of IGBT modules on the reliability of power inverters......An IGBT module has typically multiple power devices for some technical and cost advantages. This kind of configurations could have an asymmetric layout, which may lead to different thermal loadings and thereby lifetime difference of the power devices. Therefore, both the power rating and lifetime...... is studied based on a 3-phase motor drive application with a 600 V, 30 A, 3-phase transfer molded IGBT module. The thermal impedances of 6 IGBTs are investigated and its effect on the thermal loadings of power devices is studied under the given mission profile. Finally, their lifetimes are estimated...

  11. Measurements of thermal parameters of solar modules

    International Nuclear Information System (INIS)

    Górecki, K; Krac, E

    2016-01-01

    In the paper the methods of measuring thermal parameters of photovoltaic panels - transient thermal impedance and the absorption factor of light-radiation are presented. The manner of realising these methods is described and the results of measurements of the considered thermal parameters of selected photovoltaic panels are presented. The influence of such selected factors as a type of the investigated panel and its mounting manner on transient thermal impedance of the considered panels is also discussed. (paper)

  12. Reduced thermal conductivity of isotopically modulated silicon multilayer structures

    DEFF Research Database (Denmark)

    Bracht, H.; Wehmeier, N.; Eon, S.

    2012-01-01

    We report measurements of the thermal conductivity of isotopically modulated silicon that consists of alternating layers of highly enriched silicon-28 and silicon-29. A reduced thermal conductivity of the isotopically modulated silicon compared to natural silicon was measured by means of time......-resolved x-ray scattering. Comparison of the experimental results to numerical solutions of the corresponding heat diffusion equations reveals a factor of three lower thermal conductivity of the isotope structure compared to natural Si. Our results demonstrate that the thermal conductivity of silicon can...

  13. Power Generator with Thermo-Differential Modules

    Science.gov (United States)

    Saiz, John R.; Nguyen, James

    2010-01-01

    A thermoelectric power generator consists of an oven box and a solar cooker/solar reflector unit. The solar reflector concentrates sunlight into heat and transfers the heat into the oven box via a heat pipe. The oven box unit is surrounded by five thermoelectric modules and is located at the bottom end of the solar reflector. When the heat is pumped into one side of the thermoelectric module and ejected from the opposite side at ambient temperatures, an electrical current is produced. Typical temperature accumulation in the solar reflector is approximately 200 C (392 F). The heat pipe then transfers heat into the oven box with a loss of about 40 percent. At the ambient temperature of about 20 C (68 F), the temperature differential is about 100 C (180 F) apart. Each thermoelectric module, generates about 6 watts of power. One oven box with five thermoelectric modules produces about 30 watts. The system provides power for unattended instruments in remote areas, such as space colonies and space vehicles, and in polar and other remote regions on Earth.

  14. Pattern-free thermal modulator via thermal radiation between Van der Waals materials

    Science.gov (United States)

    Liu, Xianglei; Shen, Jiadong; Xuan, Yimin

    2017-10-01

    Modulating heat flux provides a platform for a plethora of emerging devices such as thermal diodes, thermal transistors, and thermal memories. Here, a pattern-free noncontact thermal modulator is proposed based on the mechanical rotation between two Van der Waals films with optical axes parallel to the surfaces. A modulation contrast can reach a value higher than 5 for hexagonal Boron Nitride (hBN) films separated by a nanoscale gap distance. The dominant radiative heat exchange comes from the excitation of both Type I and Type II hyperbolic surface phonon polaritons (HSPhPs) at the vacuum-hBN interface for different orientations, while the large modulation contrast is mainly attributed to the mismatching Type I HSPhPs induced by rotation. This work opens the possibility to design cheap thermal modulators without relying on nanofabrication techniques, and paves the way to apply natural Van der Waals materials in manipulating heat currents in an active way.

  15. Availability of thermal power plants

    International Nuclear Information System (INIS)

    Nitsch, D.; Schmitz, H.

    1981-01-01

    Availability data based on unique uniform, and clearly defined concepts and methods of acquisition have been compiled by the VGB since 1970. The data are published in anual reports. These reports contain availability data of fossil-fuelled units, combined gas/steam units, nuclear power plants, and gas turbine plants in Germany and abroad, listed by unit size fuel type, time of operation, and application. For the purpose of comparison, the data for the years since 1970 are presented as well as data averaged for the whole period under report. The main results for the year 1980 are presented now that the greater part of the plants has been evaluated. The complete evaluation will be published towards the end of 1981. (orig.) [de

  16. High-Temperature, Wirebondless, Ultracompact Wide Bandgap Power Semiconductor Modules

    Science.gov (United States)

    Elmes, John

    2015-01-01

    Silicon carbide (SiC) and other wide bandgap semiconductors offer great promise of high power rating, high operating temperature, simple thermal management, and ultrahigh power density for both space and commercial power electronic systems. However, this great potential is seriously limited by the lack of reliable high-temperature device packaging technology. This Phase II project developed an ultracompact hybrid power module packaging technology based on the use of double lead frames and direct lead frame-to-chip transient liquid phase (TLP) bonding that allows device operation up to 450 degC. The new power module will have a very small form factor with 3-5X reduction in size and weight from the prior art, and it will be capable of operating from 450 degC to -125 degC. This technology will have a profound impact on power electronics and energy conversion technologies and help to conserve energy and the environment as well as reduce the nation's dependence on fossil fuels.

  17. A review of passive thermal management of LED module

    NARCIS (Netherlands)

    Ye, H.; Sau, K.; Zeijl, H. van; Gielen, A.W.J.; Zhang, G.

    2011-01-01

    Recently, the high-brightness LEDs have begun to be designed for illumination application. The increased electrical currents used to drive LEDs lead to thermal issues. Thermal management for LED module is a key design parameter as high operation temperature directly affects their maximum light

  18. solar thermal power systems advanced solar thermal technology project, advanced subsystems development

    Science.gov (United States)

    1979-01-01

    The preliminary design for a prototype small (20 kWe) solar thermal electric generating unit was completed, consisting of several subsystems. The concentrator and the receiver collect solar energy and a thermal buffer storage with a transport system is used to provide a partially smoothed heat input to the Stirling engine. A fossil-fuel combustor is included in the receiver designs to permit operation with partial or no solar insolation (hybrid). The engine converts the heat input into mechanical action that powers a generator. To obtain electric power on a large scale, multiple solar modules will be required to operate in parallel. The small solar electric power plant used as a baseline design will provide electricity at remote sites and small communities.

  19. Thermal performance of the Atlas SCT forward modules

    CERN Document Server

    Clark, A; Nasteva, I; Snow, S W; Wallny, R; Wilmut, I

    2003-01-01

    We describe the thermal design of the Atlas SCT forward modules and their cooling blocks. We report on the performance of the $C_3 F_8$ evaporative cooling system and the blocks alone, then on the performance of an irradiated inner module mounted on two alternative prototype cooling blocks (baseline and PEEK split). Runs are presented at different cooling conditions, representative of those expected to be used in the final experiment. We have also measured thermal runaway, with the module mounted on the PEEK split block and cooled with liquid cooling.

  20. Method and apparatus for thermal power generation

    International Nuclear Information System (INIS)

    1981-01-01

    A thermal power plant reheat cycle system is described in which the discharge from a first expansion stage is reheated prior to expansion in a subsequent expansion stage. The primary coolant has a high sheet transfer rate and can accommodate temperature changes in the reheat vapor. (U.K.)

  1. Method and apparatus for thermal power generation

    International Nuclear Information System (INIS)

    Mangus, J.D.

    1979-01-01

    A method is described for power generation from a recirculating superheat-reheat circuit with multiple expansion stages which alleviates complex control systems and minimizes thermal cycling of system components, particularly the reheater. The invention includes preheating cold reheat fluid from the first expansion stage prior to its entering the reheater with fluid from the evaporator or drum component

  2. SMES based power modulator - status August 2001

    International Nuclear Information System (INIS)

    Juengst, K.P.; Gehring, R.; Kudymow, A.; Suess, E.

    2001-10-01

    Based on a superconducting magnetic energy storage (SMES) a long-pulse klystron modulator has been designed for use in the TESLA test facility (TTF) at DESY, Hamburg. A proto-type with an output power of 25 MW is under development at Forschungszentrum Karlsruhe in cooperation with the office of engineering lbK at Karlsruhe. Including a pulse transformer (1:13/11.5), the system will deliver pulses of 130 kV or 115 kV, 1.7 ms pulse length with a flat top of ± 0.5%, at a repetition rate up to 10 Hz. This new system's main features are a highly dynamic SMES (> 100 T/s), a high current power supply (rated 27 V/2.6 kA), a switched-mode high voltage power supply (rated 14 kV/45 A), a fast thyristor power switch for 2.6 kA approx. continuous current/ 2 ms break, an IGCT power switch rated 2.6 kA/14 kV, a protection switch unit and a system control unit. This demonstration system is to serve alternatively two klystrons of 5 MW RF output or one multibeam klystron of 10 MW RF output. A significant part of the components of the system has been built. A first set of the system components had been arranged to form a model of the modulator and 1 MW pulses were generated. The next large step in the area of the power electronic part is to increase the power of this test arrangement up to 10 MW. The SMES and its cryostat have undergone initial testing. The data acquisition and control system under development at DESY has been taken over and adjusted to our computer and experimental environment. (orig.)

  3. Availability statistics for thermal power plants

    International Nuclear Information System (INIS)

    1989-01-01

    Denmark, Finland and Sweden have adopted almost the same methods of recording and calculation of availability data. For a number of years comparable availability and outage data for thermal power have been summarized and published in one report. The purpose of the report now presented for 1989 containing general statistical data is to produce basic information on existing kinds of thermal power in the countries concerned. With this information as a basis additional and more detailed information can be exchanged in direct contacts between bodies in the above mentioned countries according to forms established for that purpose. The report includes fossil steam power, nuclear power and gas turbines. The information is presented in separate diagrams for each country, but for plants burning fossil fuel also in a joint NORDEL statistics with data grouped according to type of fuel used. The grouping of units into classes of capacity has been made in accordance with the classification adopted by UNIPEDE/WEC. Values based on energy have been adopted as basic availability data. The same applies to the preference made in the definitions outlined by UNIPEDE and UNIPEDE/WEC. Some data based on time have been included to make possible comparisons with certain international values and for further illustration of the performance. For values given in the report, the definitions in the NORDEL document ''Concepts of Availability for Thermal Power, September 1977'', have been applied. (author)

  4. Numerical simulations on the temperature gradient and thermal stress of a thermoelectric power generator

    International Nuclear Information System (INIS)

    Wu, Yongjia; Ming, Tingzhen; Li, Xiaohua; Pan, Tao; Peng, Keyuan; Luo, Xiaobing

    2014-01-01

    Highlights: • An appropriate ceramic plate thickness is effective in alleviating the thermal stress. • A smaller distance between thermo-pins can help prolong lifecycle of the TE module. • Either a thicker or a thinner copper conducting strip effectively reduces thermal stress. • A suitable tin soldering thickness will alleviate thermal stress intensity and increase thermal efficiency. - Abstract: Thermoelectric generator is a device taking advantage of the temperature difference in thermoelectric material to generate electric power, where the higher the temperature difference of the hot-cold ends, the higher the efficiency will be. However, higher temperature or higher heat flux upon the hot end will cause strong thermal stress which will negatively influence the lifecycle of the thermoelectric module. This phenomenon is very common in industrial applications but seldom has research work been reported. In this paper, numerical analysis on the thermodynamics and thermal stress performance of the thermoelectric module has been performed, considering the variation on the thickness of materials; the influence of high heat flux on thermal efficiency, power output, and thermal stress has been examined. It is found that under high heat flux imposing upon the hot end, the thermal stress is so strong that it has a decisive effect on the life expectation of the device. To improve the module’s working condition, different geometrical configurations are tested and the optimum sizes are achieved. Besides, the side effects on the efficiency, power output, and open circuit voltage output of the thermoelectric module are taken into consideration

  5. Environmental effects of thermal power plants

    International Nuclear Information System (INIS)

    Gerlitzky, M.; Friedrich, R.; Unger, H.

    1986-02-01

    Reviewing critically the present literature, the effects of thermal power plants on the environment are studied. At first, the loads of the different power plant types are compiled. With regard to the effects of emission reduction proceedings the pollutant emissions are quantified. The second chapter shows the effects on the ecological factors, which could be caused by the most important emission components of thermal power plants. Where it is possible, relations between immissions respectively depositions and their effects on climate, man, flora, fauna and materials will be given. This shows that many effects depend strongly on the local landscape, climate and use of natural resources. Therefore, it appears efficient to ascertain different load limits. The last chapter gives a suggestion for an ecological compatibility test (ECT) of thermal power plants. In modular form the ECT deals with the emission fields, waste heat, pollution burden of air and water, noise, loss of area and aesthetical aspects. Limits depending on local conditions and use of area will be discussed. (orig.) [de

  6. Effect of Asymmetric Layout of IGBT Modules on Reliability of Power Inverters in Motor Drive System

    DEFF Research Database (Denmark)

    Choi, Uimin; Vernica, Ionut; Blaabjerg, Frede

    2018-01-01

    An IGBT module has typically multiple power devices for some technical and cost advantages. This kind of configurations could have an asymmetric layout, which may lead to different thermal loadings and thereby lifetime difference of the power devices. Therefore, both the power rating and lifetime...... of inverters are limited by the most stressed devices. However, generally common data is provided for all devices and this may cause improper design of the inverters in terms of power rating and lifetime. In this paper, the effect of an asymmetric layout of IGBT modules on the reliability of power inverters...

  7. Optimization Tool for Direct Water Cooling System of High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Blaabjerg, Frede

    2016-01-01

    important issue for thermal design engineers. This paper aims to present a user friendly optimization tool for direct water cooling system of a high power module which enables the cooling system designer to identify the optimized solution depending on customer load profiles and available pump power. CFD...

  8. Thermal power stations and environmental protection

    International Nuclear Information System (INIS)

    Gerking, E.

    1975-01-01

    In this book, the advantages of an optimum cooling concept for waters are compared with the disadvantages of an uncontrolled thermal pollution of waters by waste waters from thermal power plants. The book focuses on the problem of the cost of measures for environmental protection which has not yet received a detailed and complete treatment. The author suggests that perfectionist solutions and superfluos measures be abandoned in favour of a far-reaching, efficient environmental protection concept with a low expenditure of fuel and capital. A detailed treatment is given to false conclusions in the present estimations of the effects of thermal pollution of the waters and to the advantages of freshwater cooling and cooling in general. Also discussed are immission problems and attempts at their solution. (ORU/AK) [de

  9. Analysis of thermal power calibration method

    International Nuclear Information System (INIS)

    Zagar, T.; Ravnik, M.; Persic, A.

    2000-01-01

    The methods for determining fuel element burnup have recently become interesting because of activities related to the shipment of highly enriched fuel elements back to the United States for final disposal before 2009. The most common and practical method for determining fuel element burnup in research reactors is reactor calculation. Experience has shown that burnup calculations become complicated and biased with uncertainties if a long period of reactor operation must be reproduced. Besides this, accuracy of calculated burnup is always limited with accuracy of reactor power calibration, since burnup calculation is based on calculated power density distribution, which is usually expressed in terms of power released per fuel element and normalised to the reactor power It is obvious that reactor thermal power calibration is very important for precise fuel element burnup calculation. Calculated fuel element burnup is linearly dependent on the thermal reactor power. The reactor power level may be determined from measured absolute thermal flux distribution across the core in the horizontal and vertical planes. Flux distributions are measured with activation of cadmium covered and bare foils irradiated by the steady reactor power. But it should be realised that this method is time consuming and not accurate. This method is practical only for zero power reactors and is in practice very seldom performed for other reactors (e.g. for TRIGA reactor in Ljubljana absolute thermal flux distribution was not performed since reactor reconstruction in 1991). In case of power reactors and research reactors in which a temperature rise across the core is produced and measured than a heat balance method is the most common and accurate method of determining the power output of the core. The purpose of this paper is to analyse the accuracy of calorimetric reactor power calibration method and to analyse the influence of control rod position on nuclear detector reading for TRIGA reactors

  10. Market: why is thermal solar power down?

    International Nuclear Information System (INIS)

    Le Jannic, N.

    2010-01-01

    After a 10 year period of steady growth the French market of the thermal solar power dropped by 15% in 2009. Only 265.000 m 2 were installed instead of 313.000 m 2 in 2008. The main reason of this decrease is the economic crisis: the European market for thermal solar energy dropped by 10%. The second reason is the unfair competition of the photovoltaic power that benefits from very favourable electricity purchase prices, from higher subsidies and from a better image in the public's eye. Another competitor on the market is the new equipment called 'thermodynamic water heater' that involves a heat pump, this equipment is cheaper but only on a short term basis. (A.C.)

  11. Modulating wind power plant output using different frequency modulation components for damping grid oscillations

    DEFF Research Database (Denmark)

    2017-01-01

    A method, controller, wind power plant, and computer program product are disclosed for operating a wind power plant comprising a plurality of wind turbines, the wind power plant producing a plant power output. The method comprises receiving a modulation request signal indicating a requested...... modulation of the plant power output, the requested modulation specifying a modulation frequency. The method further comprises generating a respective power reference signal for each of at least two wind turbines of the plurality of wind turbines selected to fulfill the requested modulation, Each generated...... power reference signal includes a respective modulation component corresponding to a portion of the requested modulation and having a frequency different than the modulation frequency....

  12. Modulation characteristics of graphene-based thermal emitters

    Science.gov (United States)

    Mahlmeister, Nathan Howard; Lawton, Lorreta Maria; Luxmoore, Isaac John; Nash, Geoffrey Richard

    2016-01-01

    We have investigated the modulation characteristics of the emission from a graphene-based thermal emitter both experimentally and through simulations using finite element method modelling. Measurements were performed on devices containing square multilayer graphene emitting areas, with the devices driven by a pulsed DC drive current over a range of frequencies. Simulations show that the dominant heat path is from the emitter to the underlying substrate, and that the thermal resistance between the graphene and the substrate determines the modulation characteristics. This is confirmed by measurements made on devices in which the emitting area is encapsulated by hexagonal boron nitride.

  13. Thermal analysis of compositionally modulated Fe/Y films

    International Nuclear Information System (INIS)

    Kajiura, M.; Morishita, T.; Togami, Y.; Tsushima, K.

    1987-01-01

    Structures of compositionally modulated Fe/Y films were studied by thermal analysis. The exothermic peak found in the DSC curve of (Fe 12 A/Y 12 A) most probably corresponds to crystallization of an amorphous material. SEM analysis suggested that the composition of crystallized (Fe 12 A/Y 12 A) was YFe2. It is concluded that a compositionally modulated (Fe 12 A/Y 12 A) is amorphous in structure as well as in magnetic properties

  14. Thermal Power:Focusing on Efficient and Clean Generation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    History review Before the foundation of New China,there was no thermal power equipment manufacturing industry in China at all.China imported the manufacturing technology of 6-MW and12-MW thermal power units from the former

  15. Availability statistics for thermal power plants

    International Nuclear Information System (INIS)

    1990-01-01

    Denmark, Finland and Sweden have adopted almost the same methods of recording and calculation of availability data. For a number of years comparable availability and outage data for thermal power have been summarized and published in one report. The purpose of the report now presented for 1990 containing general statistical data is to produce basic information on existing kinds of thermal power in the countries concerned. With this information as a basis additional and more detailed information can be exchanged in direct contacts between bodies in the above mentioned countries according to forms established for that purpose. The report includes fossil steam power, nuclear power and gas turbines. The information is presented in separate diagrams for each country, but for plants burning fossil fuel also in a joint NORDEL statistics with data grouped according to type of fuel used. The grouping of units into classes of capacity has been made in accordance with the classification adopted by UNIPEDE/WEC. Values based on energy have been adopted as basic availability data. The same applied to the preference made in the definitions outlined by UNIPEDE and UNIPEDE/WEC. Some data based on time have been included to make possible comparisons with certain international values and for futher illustration of the performance. (au)

  16. Modelling and Improvement of Thermal Cycling in Power Electronics for Motor Drive Applications

    DEFF Research Database (Denmark)

    Vernica, Ionut; Ma, Ke; Blaabjerg, Frede

    2016-01-01

    It is well known that the dynamical change of the thermal stress in the power devices is one of the major factors that have influences on the overall efficiency and reliability of power electronics. The main objective of this paper consists of identifying the main parameters that affect the thermal...... are identified during the acceleration and deceleration periods of the motor. The main causes for these adverse thermal cycles have been presented and, consequently, the influence of the deceleration slope, modulation technique and reactive current on the thermal cycles has been analyzed. Finally, the improved...

  17. Environmental protection in thermal power plants

    International Nuclear Information System (INIS)

    1987-01-01

    This workbook is a compilation of the most important facts and data that are relevant today for environmental protection in thermal power plants. Unlike the other issues the text is not in the form of a random collection of data but in the form of a complete presentation. Possible elaboration projects for pupils can be easily derived from the individual sections. These deal with: the discussion about environmental protection; forest decline; sources of emission; nuisances in the Federal Republic of Germany; environmental protection in fossil-fuel power plants - clean air - cooling water utilization and water protection - noise; environmental protection in nuclear power plants - radioactive material produced in nuclear reactors and the retention of such materials - radioactive waste materials - monitoring of radioactive emissions; accessory materials and hints. (orig./HSCH) [de

  18. Processing and characterization of device solder interconnection and module attachment for power electronics modules

    Science.gov (United States)

    Haque, Shatil

    This research is focused on the processing of an innovative three-dimensional packaging architecture for power electronics building blocks with soldered device interconnections and subsequent characterization of the module's critical interfaces. A low-cost approach termed metal posts interconnected parallel plate structure (MPIPPS) was developed for packaging high-performance modules of power electronics building blocks (PEBB). The new concept implemented direct bonding of copper posts, not wire bonding of fine aluminum wires, to interconnect power devices as well as joining the different circuit planes together. We have demonstrated the feasibility of this packaging approach by constructing PEBB modules (consisting of Insulated Gate Bipolar Transistors (IGBTs), diodes, and a few gate driver elements and passive components). In the 1st phase of module fabrication with IGBTs with Si3N 4 passivation, we had successfully fabricated packaged devices and modules using the MPIPPS technique. These modules were tested electrically and thermally, and they operated at pulse-switch and high power stages up to 6kW. However, in the 2nd phase of module fabrication with polyimide passivated devices, we experienced significant yield problems due to metallization difficulties of these devices. The under-bump metallurgy scheme for the development of a solderable interface involved sputtering of Ti-Ni-Cu and Cr-Cu, and an electroless deposition of Zn-Ni-Au metallization. The metallization process produced excellent yield in the case of Si3N4 passivated devices. However, under the same metallization schemes, devices with a polyimide passivation exhibited inconsistent electrical contact resistance. We found that organic contaminants such as hydrocarbons remain in the form of thin monolayers on the surface, even in the case of as-received devices from the manufacturer. Moreover, in the case of polyimide passivated devices, plasma cleaning introduced a few carbon constituents on the

  19. The Feasibility Study on Thermal Loading Control of Wind Power Converters with a Flexible Switching Frequency

    DEFF Research Database (Denmark)

    Qin, Zian; Wang, Huai; Blaabjerg, Frede

    2015-01-01

    Thermal loading of wind power converters is critical to their reliability performance. Especially for IGBT modules applied in a converter, both of the mean value and variation of the junction temperature have significant impact on the lifetime. Besides other strategies to reduce the thermal loadi...... the temperature fluctuations due to wind speed variations. The trade-off between the reduced amplitude of temperature fluctuations and the additional power losses that may be introduced is quantitatively studied....

  20. Availability Performance Analysis of Thermal Power Plants

    Science.gov (United States)

    Bhangu, Navneet Singh; Singh, Rupinder; Pahuja, G. L.

    2018-03-01

    This case study presents the availability evaluation method of thermal power plants for conducting performance analysis in Indian environment. A generic availability model has been proposed for a maintained system (thermal plants) using reliability block diagrams and fault tree analysis. The availability indices have been evaluated under realistic working environment using inclusion exclusion principle. Four year failure database has been used to compute availability for different combinatory of plant capacity, that is, full working state, reduced capacity or failure state. Availability is found to be very less even at full rated capacity (440 MW) which is not acceptable especially in prevailing energy scenario. One of the probable reason for this may be the difference in the age/health of existing thermal power plants which requires special attention of each unit from case to case basis. The maintenance techniques being used are conventional (50 years old) and improper in context of the modern equipment, which further aggravate the problem of low availability. This study highlights procedure for finding critical plants/units/subsystems and helps in deciding preventive maintenance program.

  1. Solar thermal and concentrated solar power barometer

    International Nuclear Information System (INIS)

    2013-01-01

    The European concentrated solar power plant market is steeling itself for tough time ahead. The number of projects under construction is a pittance compared with 2012 that was an excellent year for installations (an additional 802.5 MW of capacity recorded). This drop is the result of the moratorium on renewable energy power plants introduced by the Spanish government. The European solar thermal market is hardly any more encouraging . EurObserv'ER holds that it slipped for the fourth year in a row (it dropped 5.5% between 2011 and 2012). The newly-installed solar thermal collector surface area in the EU now stands at 3.4 million m 2 , far short of its 2008 installation record of 4.6 million m 2 . The EU's solar thermal base to date at the end of 2012 is 29.6 GWth with 2.4 GWth installed during the year 2012. This article gives tables gathering the figures of the production for every European country for 2012 and describes the market and the general trend for every EU member

  2. Development of Light Powered Sensor Networks for Thermal Comfort Measurement

    Directory of Open Access Journals (Sweden)

    Dasheng Lee

    2008-10-01

    Full Text Available Recent technological advances in wireless communications have enabled easy installation of sensor networks with air conditioning equipment control applications. However, the sensor node power supply, through either power lines or battery power, still presents obstacles to the distribution of the sensing systems. In this study, a novel sensor network, powered by the artificial light, was constructed to achieve wireless power transfer and wireless data communications for thermal comfort measurements. The sensing node integrates an IC-based temperature sensor, a radiation thermometer, a relative humidity sensor, a micro machined flow sensor and a microprocessor for predicting mean vote (PMV calculation. The 935 MHz band RF module was employed for the wireless data communication with a specific protocol based on a special energy beacon enabled mode capable of achieving zero power consumption during the inactive periods of the nodes. A 5W spotlight, with a dual axis tilt platform, can power the distributed nodes over a distance of up to 5 meters. A special algorithm, the maximum entropy method, was developed to estimate the sensing quantity of climate parameters if the communication module did not receive any response from the distributed nodes within a certain time limit. The light-powered sensor networks were able to gather indoor comfort-sensing index levels in good agreement with the comfort-sensing vote (CSV preferred by a human being and the experimental results within the environment suggested that the sensing system could be used in air conditioning systems to implement a comfort-optimal control strategy.

  3. Module-Integrated Power Converters Based on Universal Dock

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Patrick; Rodriguez, Fernando

    2015-03-13

    Solar power installations using alternating current photovoltaic (ACPV) modules have significant cost and performance advantages over systems using conventional solar modules and string inverters. ACPV modules have improved energy harvest due to module-level power point tracking and redundancy. More importantly, ACPV modules are easier and cheaper to install, lowering the total installed cost, indirect costs, and barriers to market entry. Furthermore, ACPV modules have communications and data logging capability, yielding module-level telemetry data that is useful in site diagnostics and other data applications. The products of these efforts were threefold. First, an advanced microinverter power topology was developed, modeled, simulated, and tested. Second, new microinverter enclosure concepts were developed and tested. Third, a new ACPV module prototype was constructed, combining the power topology and the enclosure concepts. SolarBridge filed for patents in each of these areas and is transitioning the project from a concept phase to full development.

  4. Thermal and electrical energy yield analysis of a directly water cooled photovoltaic module

    Directory of Open Access Journals (Sweden)

    Mtunzi Busiso

    2016-01-01

    Full Text Available Electrical energy of photovoltaic modules drops by 0.5% for each degree increase in temperature. Direct water cooling of photovoltaic modules was found to give improved electrical and thermal yield. A prototype was put in place to analyse the field data for a period of a year. The results showed an initial high performance ratio and electrical power output. The monthly energy saving efficiency of the directly water cooled module was found to be approximately 61%. The solar utilisation of the naturally cooled photovoltaic module was found to be 8.79% and for the directly water cooled module its solar utilisation was 47.93%. Implementation of such systems on households may reduce the load from the utility company, bring about huge savings on electricity bills and help in reducing carbon emissions.

  5. Solar thermal electric power information user study

    Energy Technology Data Exchange (ETDEWEB)

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1981-02-01

    The results of a series of telephone interviews with groups of users of information on solar thermal electric power are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from five solar thermal electric power groups of respondents are analyzed: DOE-Funded Researchers, Non-DOE-Funded Researchers, Representatives of Utilities, Electric Power Engineers, and Educators. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  6. Power module assembly with reduced inductance

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Terence G.; Stancu, Constantin C.; Jaksic, Marko; Mann, Brooks S.

    2018-03-13

    A power module assembly has a plurality of electrically conducting layers, including a first layer and a third layer. One or more electrically insulating layers are operatively connected to each of the plurality of electrically conducting layers. The electrically insulating layers include a second layer positioned between and configured to electrically isolate the first and the third layers. The first layer is configured to carry a first current flowing in a first direction. The third layer is configured to carry a second current flowing in a second direction opposite to the first direction, thereby reducing an inductance of the assembly. The electrically insulating layers may include a fourth layer positioned between and configured to electrically isolate the third layer and a fifth layer. The assembly results in a combined substrate and heat sink structure. The assembly eliminates the requirements for connections between separate substrate and heat sink structures.

  7. Photovoltaic thermal module concepts and their performance analysis: A review

    International Nuclear Information System (INIS)

    Hasan, M. Arif; Sumathy, K.

    2010-01-01

    This paper presents a review of the available literature covering the latest module aspects of different photovoltaic/thermal (PV/T) collectors and their performances in terms of electrical as well as thermal output. The review covers detailed description of flat-plate and concentrating PV/T systems, using liquid or air as the working fluid, numerical model analysis, experimental work and qualitative evaluation of thermal and electrical output. Also an in-depth review on the performance parameters such as, optimum mass flow rate, PV/T dimensions, air channel geometry is presented in this study. Based on the thorough review, it is clear that PV/T modules are very promising devices and there exists lot of scope to further improve their performances. Appropriate recommendations are made which will aid PV/T systems to improve their efficiency and reducing their cost, making them more competitive in the present market. (author)

  8. Photovoltaic thermal module concepts and their performance analysis: A review

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, M. Arif; Sumathy, K. [Department of Mechanical Engineering, North Dakota State University, Fargo, ND (United States)

    2010-09-15

    This paper presents a review of the available literature covering the latest module aspects of different photovoltaic/thermal (PV/T) collectors and their performances in terms of electrical as well as thermal output. The review covers detailed description of flat-plate and concentrating PV/T systems, using liquid or air as the working fluid, numerical model analysis, experimental work and qualitative evaluation of thermal and electrical output. Also an in-depth review on the performance parameters such as, optimum mass flow rate, PV/T dimensions, air channel geometry is presented in this study. Based on the thorough review, it is clear that PV/T modules are very promising devices and there exists lot of scope to further improve their performances. Appropriate recommendations are made which will aid PV/T systems to improve their efficiency and reducing their cost, making them more competitive in the present market. (author)

  9. Modelling of Power Fluxes during Thermal Quenches

    International Nuclear Information System (INIS)

    Konz, C.; Coster, D. P.; Lackner, K.; Pautasso, G.

    2005-01-01

    Plasma disruptions, i. e. the sudden loss of magnetic confinement, are unavoidable, at least occasionally, in present day and future tokamaks. The expected energy fluxes to the plasma facing components (PFCs) during disruptions in ITER lie in the range of tens of GW/m''2 for timescales of about a millisecond. Since high energy fluxes can cause severe damage to the PFCs, their design heavily depends on the spatial and temporal distribution of the energy fluxes during disruptions. We investigate the nature of power fluxes during the thermal quench phase of disruptions by means of numerical simulations with the B2 SOLPS fluid code. Based on an ASDEX Upgrade shot, steady-state pre-disruption equilibria are generated which are then subjected to a simulated thermal quench by artificially enhancing the perpendicular transport in the ion and electron channels. The enhanced transport coefficients flows the Rechester and Rosenbluth model (1978) for ergodic transport in a tokamak with destroyed flux surfaces, i. e. χ, D∼const. xT''5/2 where the constants differ by the square root of the mass ratio for ions and electrons. By varying the steady-state neutral puffing rate we can modify the divertor conditions in terms of plasma temperature and density. Our numerical findings indicate that the disruption characteristics depend on the pre disruptive divertor conditions. We study the timescales and the spatial distribution of the divertor power fluxes. The simulated disruptions show rise and decay timescales in the range observed at ASDEX Upgrade. The decay timescale for the central electron temperature of ∼800 μs is typical for non-ITB disruptions. Varying the divertor conditions we find a distinct transition from a regime with symmetric power fluxes to inboard and outboard divertors to a regime where the bulk of the power flux goes to the outboard divertor. This asymmetry in the divertor peak fluxes for the higher puffing case is accompanied by a time delay between the

  10. Increasing the efficiency of thermal power stations

    International Nuclear Information System (INIS)

    Schwarz, N.F.

    1984-01-01

    High energy prices and an increased investment of costs in power plants as well as the necessity to minimize all kinds of environmental pollution have severe consequences on the construction and operation of thermal power stations. One of the most promising measures to cope with the mentioned problems is to raise the thermal efficiency of power plants. With the example of an Austrian electric utility it can be shown that by application of high efficiency combined cycles primary energy can be converted into electricity in a most efficient manner. Excellent operating experience has proved the high reliability of these relatively complex systems. Raising the temperature of the gas topping process still higher will not raise the efficiency considerably. In this respect a Rankine cycle is superior to a Brayton cycle. In a temperature range of 850 to 900 0 C were conventional materials with known properties can still be used, only the alkali metals cesium and potassium have the necessary physical and thermodynamic properties for application in Rankine topping cycles. Building on experience gained in the Fast Breeder development and from the US space program, a potassium topping cycle linked to a conventional water steam cycle with an intermediate diphenyl vapour cycle has been proposed which should give thermal efficiencies in excess of 50%. In a multi-national program this so called Treble Rankine Cycle is being investigated under the auspices of the International Energy Agency. Work is in progress to investigate the technical and economic feasibility of this energy conversion system. Experimental investigations are already under way in the Austrian Research Center Seibersdorf where high temperature liquid metal test facilities have been operated since 1968. (Author)

  11. Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

    Science.gov (United States)

    Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

    2011-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

  12. Thermal power plants and acid rain

    International Nuclear Information System (INIS)

    Ataman, Eleonora

    1990-01-01

    The slow acidification of the environment and the frequent occurrence of the precipitation with pH lower than 5.6 over areas continuously extending are caused by the pollutant releases, especially SO 2 and NO x from anthropic sources. There is a relationship between the SO 2 release from the high stacks of thermal power plants and the long-range transfrontier pollution. The most efficient method to avoid damage on environment is to reduce the releases from stationary and mobile sources. (author)

  13. Modeling of a Stacked Power Module for Parasitic Inductance Extraction

    Science.gov (United States)

    2017-09-15

    ARL-TR-8138 ● SEP 2017 US Army Research Laboratory Modeling of a Stacked Power Module for Parasitic Inductance Extraction by...not return it to the originator. ARL-TR-8138 ● SEP 2017 US Army Research Laboratory Modeling of a Stacked Power Module for... Power Module for Parasitic Inductance Extraction 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Steven Kaplan

  14. Source driven breeding thermal power reactors

    International Nuclear Information System (INIS)

    Greenspan, E.; Schneider, A.; Misulovin, A.; Gilai, D.; Levin, P.; Ben-Gurion Univ. of the Negev, Beersheba

    1978-03-01

    Improvements in the performance of fission power reactors made possible by designing them subcritical driven by D-T neutron sources are investigated. Light-water thermal systems are found to be most promising, neutronically and energetically, for the source driven mode of operation. The range of performance characteristics expected from breeding Light Water Hybrid Reactors (LWHR) is defined. Several promising types of LWHR blankets are identified. Options opened for the nuclear energy strategy by four types of the LWHRs are examined, and the potential contribution of these LWHRs to the nuclear energy economy are discussed. The power systems based on these LWHRs are found to enable a high utilization of the energy content of the uranium resources in all forms available - including depleted uranium and spent fuel from LWRs, while being free from the need for uranium enrichment and plutonium separation capabilities. (author)

  15. Market Power in Hydro-Thermal Supply

    International Nuclear Information System (INIS)

    Edin, Karl-Axel

    2006-12-01

    Despite having had a deregulated electricity market in Sweden for over ten years we still need to increase our understanding as to how deregulated electricity markets actually work and how possible problems are to be solved. One question that is always in focus is if the competition between generators in the Nordic electricity market really works the way it was intended. Many argue that the concentration in ownership of generation plants already has gone too far. Together with joint ownership in nuclear facilities and barriers for entrance, critics say that this has resulted in higher electricity prices than necessary. In this report different methods to (ex ante) study potential possibilities for generating firms to influence the electricity price (market power) and (ex post) discover possible manipulation through analysing the spot price and other observed factors on the electricity market are analysed. The purpose of the longer underlying paper is to give a comprehensive treatment of the electricity market with storage, i.e. hydro power, with an auction market organisation and to test the models on the Nordic market in order to explore the explanatory power of auction market theory and the theory of contestable market. The main theoretical effort in the paper concerns auction theory with inventories. The paper develops an inter-temporal auction model of a thermal-hydro power market. Parallel to the derivation of the basic equations a numerical model is developed in order to illustrate the results of the model. Section 2 of the present paper summarizes the basic equations (derived in the longer paper) for an inter-temporal auction thermal-hydro market. Section 3 contains the illustrations of solutions to equations for some stylized markets. In section 4 the auction model is tested on the Nordic market

  16. Microfabricated thermal modulator for comprehensive two-dimensional micro gas chromatography: design, thermal modeling, and preliminary testing.

    Science.gov (United States)

    Kim, Sung-Jin; Reidy, Shaelah M; Block, Bruce P; Wise, Kensall D; Zellers, Edward T; Kurabayashi, Katsuo

    2010-07-07

    In comprehensive two-dimensional gas chromatography (GC x GC), a modulator is placed at the juncture between two separation columns to focus and re-inject eluting mixture components, thereby enhancing the resolution and the selectivity of analytes. As part of an effort to develop a microGC x microGC prototype, in this report we present the design, fabrication, thermal operation, and initial testing of a two-stage microscale thermal modulator (microTM). The microTM contains two sequential serpentine Pyrex-on-Si microchannels (stages) that cryogenically trap analytes eluting from the first-dimension column and thermally inject them into the second-dimension column in a rapid, programmable manner. For each modulation cycle (typically 5 s for cooling with refrigeration work of 200 J and 100 ms for heating at 10 W), the microTM is kept approximately at -50 degrees C by a solid-state thermoelectric cooling unit placed within a few tens of micrometres of the device, and heated to 250 degrees C at 2800 degrees C s(-1) by integrated resistive microheaters and then cooled back to -50 degrees C at 250 degrees C s(-1). Thermal crosstalk between the two stages is less than 9%. A lumped heat transfer model is used to analyze the device design with respect to the rates of heating and cooling, power dissipation, and inter-stage thermal crosstalk as a function of Pyrex-membrane thickness, air-gap depth, and stage separation distance. Experimental results are in agreement with trends predicted by the model. Preliminary tests using a conventional capillary column interfaced to the microTM demonstrate the capability for enhanced sensitivity and resolution as well as the modulation of a mixture of alkanes.

  17. Mirage effect from thermally modulated transparent carbon nanotube sheets.

    Science.gov (United States)

    Aliev, Ali E; Gartstein, Yuri N; Baughman, Ray H

    2011-10-28

    The single-beam mirage effect, also known as photothermal deflection, is studied using a free-standing, highly aligned carbon nanotube aerogel sheet as the heat source. The extremely low thermal capacitance and high heat transfer ability of these transparent forest-drawn carbon nanotube sheets enables high frequency modulation of sheet temperature over an enormous temperature range, thereby providing a sharp, rapidly changing gradient of refractive index in the surrounding liquid or gas. The advantages of temperature modulation using carbon nanotube sheets are multiple: in inert gases the temperature can reach > 2500 K; the obtained frequency range for photothermal modulation is ~100 kHz in gases and over 100 Hz in high refractive index liquids; and the heat source is transparent for optical and acoustical waves. Unlike for conventional heat sources for photothermal deflection, the intensity and phase of the thermally modulated beam component linearly depends upon the beam-to-sheet separation over a wide range of distances. This aspect enables convenient measurements of accurate values for thermal diffusivity and the temperature dependence of refractive index for both liquids and gases. The remarkable performance of nanotube sheets suggests possible applications as photo-deflectors and for switchable invisibility cloaks, and provides useful insights into their use as thermoacoustic projectors and sonar. Visibility cloaking is demonstrated in a liquid.

  18. Power Electronics and Thermal Management | Transportation Research | NREL

    Science.gov (United States)

    Power Electronics and Thermal Management Power Electronics and Thermal Management This is the March Gearhart's testimony. Optical Thermal Characterization Enables High-Performance Electronics Applications New vehicle electronics systems are being developed at a rapid pace, and NREL is examining strategies to

  19. Current Sharing inside a High Power IGBT Module at the Negative Temperature Coefficient Operating Region

    CERN Document Server

    AUTHOR|(CDS)2084596; Papastergiou, Konstantinos; Bongiorno, M; Thiringer, T

    2016-01-01

    This work investigates the current sharing effect of a high power Soft Punch Through IGBT module in the Negative Temperature Coefficient region. The unbalanced current sharing between two of the substrates is demonstrated for different current and temperature levels and its impact on the thermal stressing of the device is evaluated. The results indicate that the current asymmetry does not lead to a significant thermal stressing unbalance between the substrates.

  20. Inverter power module with distributed support for direct substrate cooling

    Science.gov (United States)

    Miller, David Harold [San Pedro, CA; Korich, Mark D [Chino Hills, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA

    2012-08-21

    Systems and/or methods are provided for an inverter power module with distributed support for direct substrate cooling. An inverter module comprises a power electronic substrate. A first support frame is adapted to house the power electronic substrate and has a first region adapted to allow direct cooling of the power electronic substrate. A gasket is interposed between the power electronic substrate and the first support frame. The gasket is configured to provide a seal between the first region and the power electronic substrate. A second support frame is adapted to house the power electronic substrate and joined to the first support frame to form the seal.

  1. Emission Control Technologies for Thermal Power Plants

    Science.gov (United States)

    Nihalani, S. A.; Mishra, Y.; Juremalani, J.

    2018-03-01

    Coal thermal power plants are one of the primary sources of artificial air emissions, particularly in a country like India. Ministry of Environment and Forests has proposed draft regulation for emission standards in coal-fired power plants. This includes significant reduction in sulphur-dioxide, oxides of nitrogen, particulate matter and mercury emissions. The first step is to evaluate the technologies which represent the best selection for each power plant based on its configuration, fuel properties, performance requirements, and other site-specific factors. This paper will describe various technology options including: Flue Gas Desulfurization System, Spray Dryer Absorber (SDA), Circulating Dry Scrubber (CDS), Limestone-based Wet FGD, Low NOX burners, Selective Non Catalytic Reduction, Electrostatic Precipitator, Bag House Dust Collector, all of which have been evaluated and installed extensively to reduce SO2, NOx, PM and other emissions. Each control technology has its advantages and disadvantages. For each of the technologies considered, major features, potential operating and maintenance cost impacts, as well as key factors that contribute to the selection of one technology over another are discussed here.

  2. Radioactive emission from thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, K [New South Wales Univ., Kensington (Australia). Dept. of Applied Mathematics

    1981-07-01

    Radioactive hazards of the emissions and wastes of thermal power plants arising from fuel impurities of uranium and thorium are discussed. The hazard due to radioactive emission is calculated for an average Australian bituminous coal which contains 2 ppm of U and 2.7 ppm of Th. When the dust removal efficiency of a coal-fired power plant is 99%, the radioactive hazard is greater than that of a nuclear reactor of the same electrical output. After 500 years the radioactive toxicity of the coal waste will be higher than that of fission products of a nuclear reactor and after 2,000 years it will exceed the toxicity of all the nuclear wastes including actinides. The results of a recent calculation are shown, according to which the radioactive hazard of a coal-fired power plant to the public is from several hundred to several tens of thousands of times higher than that of a total fuel cycle of plutonium. It is found that in some regions, such as Japan, the hazard due to /sup 210/Po through seafood could be considerable.

  3. Longitudinal On-Column Thermal Modulation for Comprehensive Two-Dimensional Liquid Chromatography.

    Science.gov (United States)

    Creese, Mari E; Creese, Mathew J; Foley, Joe P; Cortes, Hernan J; Hilder, Emily F; Shellie, Robert A; Breadmore, Michael C

    2017-01-17

    Longitudinal on-column thermal modulation for comprehensive two-dimensional liquid chromatography is introduced. Modulation optimization involved a systematic investigation of heat transfer, analyte retention, and migration velocity at a range of temperatures. Longitudinal on-column thermal modulation was realized using a set of alkylphenones and compared to a conventional valve-modulator employing sample loops. The thermal modulator showed a reduced modulation-induced pressure impact than valve modulation, resulting in reduced baseline perturbation by a factor of 6; yielding a 6-14-fold improvement in signal-to-noise. A red wine sample was analyzed to demonstrate the potential of the longitudinal on-column thermal modulator for separation of a complex sample. Discrete peaks in the second dimension using the thermal modulator were 30-55% narrower than with the valve modulator. The results shown herein demonstrate the benefits of an active focusing modulator, such as reduced detection limits and increased total peak capacity.

  4. Modelling and Design of Active Thermal Controls for Power Electronics of Motor Drive Applications

    DEFF Research Database (Denmark)

    Vernica, Ionut; Blaabjerg, Frede; Ma, Ke

    2017-01-01

    of active thermal control methods for the power devices of a motor drive application. The motor drive system together with the thermal cycling of the power devices have been modelled, and adverse temperature swings could be noticed during the start-up and deceleration periods of the motor. Based...... on the electrical response of the system, the junction temperature of the semiconductor devices is estimated, and consequently three active thermal control methods are proposed and practically designed with respect to the following parameters: switching frequency, deceleration slope and modulation technique....... Finally, experimental results are provided in order to validate the effectiveness of the proposed control methods....

  5. Outdoor thermal and electrical characterisation of photovoltaic modules and systems

    OpenAIRE

    Herteleer, Bert

    2016-01-01

    Current and future investors in photovoltaic systems are interested in how well the system performs, and how predictable this is over the expected lifetime. To do so, models have been developed and measurements of photovoltaic systems have been done. This dissertation presents the outdoor measurement set-up that has been developed for thermal and electrical characterisation of photovoltaic modules and systems, aimed at measuring transient effects and changes. The main design decisions and ...

  6. Lunar Module Electrical Power System Design Considerations and Failure Modes

    Science.gov (United States)

    Interbartolo, Michael

    2009-01-01

    This slide presentation reviews the design and redesign considerations of the Apollo lunar module electrical power system. Included in the work are graphics showing the lunar module power system. It describes the in-flight failures, and the lessons learned from these failures.

  7. Thermal modelling of PV module performance under high ambient temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Diarra, D.C.; Harrison, S.J. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering Solar Calorimetry Lab; Akuffo, F.O. [Kwame Nkrumah Univ. of Science and Technology, Kumasi (Ghana). Dept. of Mechanical Engineering

    2005-07-01

    When predicting the performance of photovoltaic (PV) generators, the actual performance is typically lower than test results conducted under standard test conditions because the radiant energy absorbed in the module under normal operation raises the temperature of the cell and other multilayer components. The increase in temperature translates to a lower conversion efficiency of the solar cells. In order to address these discrepancies, a thermal model of a characteristic PV module was developed to assess and predict its performance under real field-conditions. The PV module consisted of monocrystalline silicon cells in EVA between a glass cover and a tedlar backing sheet. The EES program was used to compute the equilibrium temperature profile in the PV module. It was shown that heat is dissipated towards the bottom and the top of the module, and that its temperature can be much higher than the ambient temperature. Modelling results indicate that 70-75 per cent of the absorbed solar radiation is dissipated from the solar cells as heat, while 4.7 per cent of the solar energy is absorbed in the glass cover and the EVA. It was also shown that the operating temperature of the PV module decreases with increased wind speed. 2 refs.

  8. Hemispherical power asymmetry from scale-dependent modulated reheating

    International Nuclear Information System (INIS)

    McDonald, John

    2013-01-01

    We propose a new model for the hemispherical power asymmetry of the CMB based on modulated reheating. Non-Gaussianity from modulated reheating can be small enough to satisfy the bound from Planck if the dominant modulation of the inflaton decay rate is linear in the modulating field σ. σ must then acquire a spatially-modulated power spectrum with a red scale-dependence. This can be achieved if the primordial perturbation of σ is generated via tachyonic growth of a complex scalar field. Modulated reheating due to σ then produces a spatially modulated and scale-dependent sub-dominant contribution to the adiabatic density perturbation. We show that it is possible to account for the observed asymmetry while remaining consistent with bounds from quasar number counts, non-Gaussianity and the CMB temperature quadupole. The model predicts that the adiabatic perturbation spectral index and its running will be modified by the modulated reheating component

  9. Thermal power sludge – properties, treatment, utilization

    Directory of Open Access Journals (Sweden)

    Martin Sisol

    2005-11-01

    Full Text Available In this paper a knowledge about properties of thermal power sludge from coal combustion in smelting boilers is presented. The physical and technological properties of slag – granularity, density, specific, volume and pouring weight, hardness and decoupling – together with chemical properties influence its exploitation. The possibility of concentrating the Fe component by the mineral processing technologies (wet low-intenzity magnetic separation is verified. An industrial use of the slag in civil engineering, e.g. road construction, was realised. The slag-fly ashes are directly utilized in the cement production as a substitute of a part of natural raw materials. For the use of slag as the stoneware in the road construction, all the criteria are fulfilled.

  10. Renewable Energy Essentials: Concentrating Solar Thermal Power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Concentrated solar thermal power (CSP) is a re-emerging market. The Luz Company built 354 MWe of commercial plants in California, still in operations today, during 1984-1991. Activity re-started with the construction of an 11-MW plant in Spain, and a 64-MW plant in Nevada, by 2006. There are currently hundreds of MW under construction, and thousands of MW under development worldwide. Spain and the United States together represent 90% of the market. Algeria, Egypt and Morocco are building integrated solar combined cycle plants, while Australia, China, India, Iran, Israel, Italy, Jordan, Mexico, South Africa and the United Arab Emirates are finalising or considering projects. While trough technology remains the dominant technology, several important innovations took place over 2007-2009: the first commercial solar towers, the first commercial plants with multi-hour capacities, the first Linear Fresnel Reflector plants went into line.

  11. The Impact of Power Switching Devices on the Thermal Performance of a 10 MW Wind Power NPC Converter

    Directory of Open Access Journals (Sweden)

    Ke Ma

    2012-07-01

    Full Text Available Power semiconductor switching devices play an important role in the performance of high power wind energy generation systems. The state-of-the-art device choices in the wind power application as reported in the industry include IGBT modules, IGBT press-pack and IGCT press-pack. Because of significant deviation in the packaging structure, electrical characteristics, as well as thermal impedance, these available power switching devices may have various thermal cycling behaviors, which will lead to converter solutions with very different cost, size and reliability performance. As a result, this paper aimed to investigate the thermal related characteristics of some important power switching devices. Their impact on the thermal cycling of a 10 MW three-level Neutral-Point-Clamped wind power converter is then evaluated under various operating conditions; the main focus will be on the grid connected inverter. It is concluded that the thermal performances of the 3L-NPC wind power converter can be significantly changed by the power device technology as well as their parallel configurations.

  12. Quantitative subsurface analysis using frequency modulated thermal wave imaging

    Science.gov (United States)

    Subhani, S. K.; Suresh, B.; Ghali, V. S.

    2018-01-01

    Quantitative depth analysis of the anomaly with an enhanced depth resolution is a challenging task towards the estimation of depth of the subsurface anomaly using thermography. Frequency modulated thermal wave imaging introduced earlier provides a complete depth scanning of the object by stimulating it with a suitable band of frequencies and further analyzing the subsequent thermal response using a suitable post processing approach to resolve subsurface details. But conventional Fourier transform based methods used for post processing unscramble the frequencies with a limited frequency resolution and contribute for a finite depth resolution. Spectral zooming provided by chirp z transform facilitates enhanced frequency resolution which can further improves the depth resolution to axially explore finest subsurface features. Quantitative depth analysis with this augmented depth resolution is proposed to provide a closest estimate to the actual depth of subsurface anomaly. This manuscript experimentally validates this enhanced depth resolution using non stationary thermal wave imaging and offers an ever first and unique solution for quantitative depth estimation in frequency modulated thermal wave imaging.

  13. Critical success factors for BOT electric power projects in China: Thermal power versus wind power

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zhen-Yu. [School of Business Administration, North China Electric Power University, Beijing 102206 (China); Zuo, Jian; Zillante, George [School of Natural and Built Environments, University of South Australia, Adelaide 5001 (Australia); Wang, Xin-Wei [Shandong Nuclear Power Equipment Manufacturing Co. Ltd, Haiyang, Shandong 265118 (China)

    2010-06-15

    Chinese electric power industry has adopted Build-Operate-Transfer (BOT) approach in a number of projects to alleviate the pressure of sole state-owned investment. The Chinese government has taken enormous efforts to create an environment to facilitate the application of BOT approach in electric power projects. Moreover, the growing attention on the sustainability issues puts the traditional major source of electricity - thermal power project under more strict scrutiny. As a result, various renewable energy projects, particularly the wind power projects have involved private sector funds. Both thermal power and wind power projects via BOT approach have met with a varying degree of success. Therefore, it is imperative to understand the factors contributing towards the success of both types of BOT power projects. Using an extensive literature survey, this paper identifies 31 success factors under 5 categories for Chinese BOT electric power projects. This is followed by a questionnaire survey to exam relative significance of these factors. The results reveal the different levels of significance of success factors for BOT thermal power projects versus wind power projects. Finally, survey results were analyzed to explore the underlying construction and distributions among the identified success factors. This study provides a valuable reference for all involved parties that are interested in developing BOT electric power projects in China. (author)

  14. International technologies market for coal thermal power plants

    International Nuclear Information System (INIS)

    1998-01-01

    This paper reports a general framework of potential market of clean coal combustion technologies in thermal power plants, specially for commercialization and market penetration in developing countries [it

  15. A Temperature-Dependent Thermal Model of IGBT Modules Suitable for Circuit-Level Simulations

    DEFF Research Database (Denmark)

    Wu, Rui; Wang, Huai; Ma, Ke

    2014-01-01

    Thermal impedance of IGBT modules may vary with operating conditions due to that the thermal conductivity and heat capacity of materials are temperature dependent. This paper proposes a Cauer thermal model for a 1700 V/1000 A IGBT module with temperature-dependent thermal resistances and thermal ...... relevant reliability aspect performance. A test bench is built up with an ultra-fast infrared (IR) camera to validate the proposed thermal impedance model....

  16. Design of a low parasitic inductance SiC power module with double-sided cooling

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Fei [The University of Tennessee, Knoxville; Liang, Zhenxian [Cree Inc.; Wang, Fei [ORNL; Wang, Zhiqiang [ORNL

    2017-03-01

    In this paper, a low-parasitic inductance SiC power module with double-sided cooling is designed and compared with a baseline double-sided cooled module. With the unique 3D layout utilizing vertical interconnection, the power loop inductance is effectively reduced without sacrificing the thermal performance. Both simulations and experiments are carried out to validate the design. Q3D simulation results show a power loop inductance of 1.63 nH, verified by the experiment, indicating more than 60% reduction of power loop inductance compared with the baseline module. With 0Ω external gate resistance turn-off at 600V, the voltage overshoot is less than 9% of the bus voltage at a load of 44.6A.

  17. Solar thermal power: the seamless solar link to the conventional power world

    International Nuclear Information System (INIS)

    Geyer, Michael; Quaschning, Volker

    2000-01-01

    This article focuses on solar thermal power generation and describes two solar thermal power concepts, namely, the parabolic trough or solar farm, and the solar central receiver or power tower. Details are given of grid-connected parabolic trough power plants in California and recent developments in collector design and absorber tubes, and the operation of power tower plants with different heat transfer media. Market issues are discussed, and solar thermal power projects under development, and application for support for solar thermal power projects under the Global Environment Facility's Operational Programme by Egypt, India, Iran, Mexico and Morocco are reported

  18. Periodic and stochastic thermal modulation of protein folding kinetics.

    Science.gov (United States)

    Platkov, Max; Gruebele, Martin

    2014-07-21

    Chemical reactions are usually observed either by relaxation of a bulk sample after applying a sudden external perturbation, or by intrinsic fluctuations of a few molecules. Here we show that the two ideas can be combined to measure protein folding kinetics, either by periodic thermal modulation, or by creating artificial thermal noise that greatly exceeds natural thermal fluctuations. We study the folding reaction of the enzyme phosphoglycerate kinase driven by periodic temperature waveforms. As the temperature waveform unfolds and refolds the protein, its fluorescence color changes due to FRET (Förster resonant Energy Transfer) of two donor/acceptor fluorophores labeling the protein. We adapt a simple model of periodically driven kinetics that nicely fits the data at all temperatures and driving frequencies: The phase shifts of the periodic donor and acceptor fluorescence signals as a function of driving frequency reveal reaction rates. We also drive the reaction with stochastic temperature waveforms that produce thermal fluctuations much greater than natural fluctuations in the bulk. Such artificial thermal noise allows the recovery of weak underlying signals due to protein folding kinetics. This opens up the possibility for future detection of a stochastic resonance for protein folding subject to noise with controllable amplitude.

  19. Electrochemical-thermal Modeling to Evaluate Active Thermal Management of a Lithium-ion Battery Module

    International Nuclear Information System (INIS)

    Bahiraei, Farid; Fartaj, Amir; Nazri, Gholam-Abbas

    2017-01-01

    Lithium-ion batteries are commonly used in hybrid electric and full electric vehicles (HEV and EV). In HEV, thermal management is a strict requirement to control the batteries temperature within an optimal range in order to enhance performance, safety, reduce cost, and prolong the batteries lifetime. The optimum design of a thermal management system depends on the thermo-electrochemical behavior of the batteries, operating conditions, and weight and volume constraints. The aim of this study is to investigate the effects of various operating and design parameters on the thermal performance of a battery module consisted of six building block cells. An electrochemical-thermal model coupled to conjugate heat transfer and fluid dynamics simulations is used to assess the effectiveness of two indirect liquid thermal management approaches under the FUDC driving cycle. In this study, a novel pseudo 3D electrochemical-thermal model of the battery is used. It is found that the cooling plate thickness has a significant effect on the maximum and gradient of temperature in the module. Increasing the Reynolds number decreases the average temperature but at the expense of temperature uniformity. The results show that double channel cooling system has a lower maximum temperature and more uniform temperature distribution compared to a single channel cooling system.

  20. Conditioned pain modulation dampens the thermal grill illusion.

    Science.gov (United States)

    Harper, D E; Hollins, M

    2017-10-01

    The thermal grill illusion (TGI) refers to the perception of burning heat and often pain that arises from simultaneous cutaneous application of innocuous warm and cool stimuli. This study utilized conditioned pain modulation (CPM) to help elucidate the TGI's underlying neural mechanisms, including the debated role of ascending nociceptive signals in generating the illusion. To trigger CPM, subjects placed the left hand in noxious cold (6 °C) water before placing the right volar forearm onto a thermal grill. Lower pain and unpleasantness ratings of the grill in this CPM run compared to those in a control run (i.e. 33 °C water) were taken as evidence of CPM. To determine whether CPM reduces noxious heat pain and illusory heat pain equally, an experimental group of subjects rated pain and unpleasantness of a grill consisting of innocuous alternating warm (42 °C) and cool (18 °C) bars, while a control group rated a grill with all bars controlled to a noxious temperature (45 °C). CPM produced significant and comparable reductions in pain, unpleasantness and perceived heat of both noxious heat and the TGI. This result suggests that the TGI results from signals in nociceptive dorsal horn convergent neurons, since CPM involves descending inhibition with high selectivity for this neuronal population. More broadly, CPM's ability to produce a shift in perceived thermal sensation of both noxious heat and the TGI from 'hot' to 'warm' implies that nociceptive signals generated by a cutaneous stimulus can contribute to its perceived thermal intensity. Conditioned pain modulation reduces the perceived painfulness, unpleasantness and heat of the thermal grill illusion and noxious heat similarly. The results have important theoretical implications for both types of pain. © 2017 European Pain Federation - EFIC®.

  1. Thermal equilibrium control by frequent bang-bang modulation.

    Science.gov (United States)

    Yang, Cheng-Xi; Wang, Xiang-Bin

    2010-05-01

    In this paper, we investigate the non-Markovian heat transfer between a weakly damped harmonic oscillator (system) and a thermal bath. When the system is initially in a thermal state and not correlated with the environment, the mean energy of the system always first increases, then oscillates, and finally reaches equilibrium with the bath, no matter what the initial temperature of the system is. Moreover, the heat transfer between the system and the bath can be controlled by fast bang-bang modulation. This modulation does work on the system, and temporarily inverts the direction of heat flow. In this case, the common sense that heat always transfers from hot to cold does not hold any more. At the long time scale, a new dynamic equilibrium is established between the system and the bath. At this equilibrium, the energy of the system can be either higher or lower than its normal equilibrium value. A comprehensive analysis of the relationship between the dynamic equilibrium and the parameters of the modulation as well as the environment is presented.

  2. Development of the ultra high efficiency thermal power generation facility

    Energy Technology Data Exchange (ETDEWEB)

    Sano, Toshihiro

    2010-09-15

    In order to prevent global warming, attention is focused on nuclear power generation and renewable energy such as wind and solar power generation. The electric power suppliers of Japan are aiming to increase the amount of nuclear and non-fossil fuel power generation over 50% of the total power generation by 2020. But this means that the remaining half will still be of thermal power generation using fossil fuel and will still play an important role. Under such circumstances, further efficiency improvement of the thermal power generation and its aggressive implementation is ongoing in Japan.

  3. Power electronics solution to dust emissions from thermal power plants

    Directory of Open Access Journals (Sweden)

    Vukosavić Slobodan

    2010-01-01

    Full Text Available Thermal power stations emit significant amounts of fly ash and ultra fine particles into the atmosphere. Electrostatic precipitators (ESP or electro filters remove flying ashes and fine particles from the flue gas before passing the gas into the chimney. Maximum allowable value of dust is 50 mg/m3 and it requires that the efficiency of the ESPs better than 99 %, which calls for an increase of active surface of the electrodes, hence increasing the filter volume and the weight of steel used for the filter. In previous decades, electrostatic precipitators in thermal power plants were fed by thyristor controlled, single phase fed devices having a high degree of reliability, but with a relatively low collection efficiency, hence requiring large effective surface of the collection plates and a large weight of steel construction in order to achieve the prescribed emission limits. Collection efficiency and energy efficiency of the electrostatic precipitator can be increased by applying high frequency high voltage power supply (HF HV. Electrical engineering faculty of the University of Belgrade (ETF has developed technology and HF HV equipment for the ESP power supply. This solution was subjected to extensive experimental investigation at TE Morava from 2008 to 2010. High frequency power supply is proven to reduce emission two times in controlled conditions while increasing energy efficiency of the precipitator, compared to the conventional thyristor controlled 50Hz supply. Two high frequency high voltage unit AR70/1000 with parameters 70 kV and 1000 mA are installed at TE Morava and thoroughly testes. It was found that the HF HV power supply of the ESP at TE Morava increases collection efficiency so that emission of fine particles and flying ashes are halved, brought down to only 50 % of the emissions encountered with conventional 50 Hz thyristor driven power supplies. On the basis of this study, conclusion is drawn that the equipment comprising HF HV

  4. Power and Thermal Management of System-on-Chip

    DEFF Research Database (Denmark)

    Liu, Wei

    , are necessary at the chip design level. In this work, we investigate the power and thermal management of System-on- Chips (SoCs). Thermal analysis is performed in a SPICE simulation approach based on the electrical-thermal analogy. We investigate the impact of inter- connects on heat distribution...

  5. Modelling and simulation of thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Eborn, J.

    1998-02-01

    Mathematical modelling and simulation are important tools when dealing with engineering systems that today are becoming increasingly more complex. Integrated production and recycling of materials are trends that give rise to heterogenous systems, which are difficult to handle within one area of expertise. Model libraries are an excellent way to package engineering knowledge of systems and units to be reused by those who are not experts in modelling. Many commercial packages provide good model libraries, but they are usually domain-specific and closed. Heterogenous, multi-domain systems requires open model libraries written in general purpose modelling languages. This thesis describes a model database for thermal power plants written in the object-oriented modelling language OMOLA. The models are based on first principles. Subunits describe volumes with pressure and enthalpy dynamics and flows of heat or different media. The subunits are used to build basic units such as pumps, valves and heat exchangers which can be used to build system models. Several applications are described; a heat recovery steam generator, equipment for juice blending, steam generation in a sulphuric acid plant and a condensing steam plate heat exchanger. Model libraries for industrial use must be validated against measured data. The thesis describes how parameter estimation methods can be used for model validation. Results from a case-study on parameter optimization of a non-linear drum boiler model show how the technique can be used 32 refs, 21 figs

  6. Cubesat SEP Power Module, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Today's CubeSats are inherently power limited due to their small size and available surface area. Today's CubeSats offer <100W of available power. This limits...

  7. Power Admission Control with Predictive Thermal Management in Smart Buildings

    DEFF Research Database (Denmark)

    Yao, Jianguo; Costanzo, Giuseppe Tommaso; Zhu, Guchuan

    2015-01-01

    This paper presents a control scheme for thermal management in smart buildings based on predictive power admission control. This approach combines model predictive control with budget-schedulability analysis in order to reduce peak power consumption as well as ensure thermal comfort. First...

  8. Frequency-domain thermal modelling of power semiconductor devices

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede; Andresen, Markus

    2015-01-01

    to correctly predict the device temperatures, especially when considering the thermal grease and heat sink attached to the power semiconductor devices. In this paper, the frequency-domain approach is applied to the modelling of thermal dynamics for power devices. The limits of the existing RC lump...

  9. High-precision thermal and electrical characterization of thermoelectric modules

    Science.gov (United States)

    Kolodner, Paul

    2014-05-01

    This paper describes an apparatus for performing high-precision electrical and thermal characterization of thermoelectric modules (TEMs). The apparatus is calibrated for operation between 20 °C and 80 °C and is normally used for measurements of heat currents in the range 0-10 W. Precision thermometry based on miniature thermistor probes enables an absolute temperature accuracy of better than 0.010 °C. The use of vacuum isolation, thermal guarding, and radiation shielding, augmented by a careful accounting of stray heat leaks and uncertainties, allows the heat current through the TEM under test to be determined with a precision of a few mW. The fractional precision of all measured parameters is approximately 0.1%.

  10. Optimization of Modulation Waveforms for Improved EMI Attenuation in Switching Frequency Modulated Power Converters

    Directory of Open Access Journals (Sweden)

    Deniss Stepins

    2015-01-01

    Full Text Available Electromagnetic interference (EMI is one of the major problems of switching power converters. This paper is devoted to switching frequency modulation used for conducted EMI suppression in switching power converters. Comprehensive theoretical analysis of switching power converter conducted EMI spectrum and EMI attenuation due the use of traditional ramp and multislope ramp modulation waveforms is presented. Expressions to calculate EMI spectrum and attenuation are derived. Optimization procedure of the multislope ramp modulation waveform is proposed to get maximum benefits from switching frequency modulation for EMI reduction. Experimental verification is also performed to prove that the optimized multislope ramp modulation waveform is very useful solution for effective EMI reduction in switching power converters.

  11. Application of double modulation for measurement of the thermal expansion coefficient of liquid metals

    International Nuclear Information System (INIS)

    Blagonravov, L A; Karchevskiy, O O; Ivannikov, P V; Soboleva, A V

    2008-01-01

    The first results of the thermal expansion coefficient measurement obtained for liquid conductors using a new modulation method are presented. The method is based on a superposition of two periodical influences on a liquid metal. The thermal expansion coefficient α P is determined by means of measuring the amplitudes of oscillations of electric current power w ∼ and pressure p ∼ . In the present work the K-Na alloy of the eutectic composition was used as a sample. Distinction of the experimental data obtained by authors from the literature data is 30 to 40%. Such a difference is in the range of error of determination of α P from the density data of K-Na alloy. The method allows direct determination of the thermal expansion coefficient of liquid conductors in absolute units

  12. Thermal Stress Analysis and Structure Parameter Selection for a Bi2Te3-Based Thermoelectric Module

    Science.gov (United States)

    Gao, Jun-Ling; Du, Qun-Gui; Zhang, Xiao-Dan; Jiang, Xin-Qiang

    2011-05-01

    The output power and conversion efficiency of thermoelectric modules (TEMs) are mainly determined by their material properties, i.e., Seebeck coefficient, electrical resistivity, and thermal conductivity. In practical applications, due to the influence of the harsh environment, the mechanical properties of TEMs should also be considered. Using the finite-element analysis (FEA) model in ANSYS software, we present the thermal stress distribution of a TEM based on the anisotropic mechanical properties and thermoelectric properties of hot-pressed materials. By analyzing the possibilities of damage along the cleavage plane of Bi2Te3-based thermoelectric materials and by optimizing the structure parameters, a TEM with better mechanical performance is obtained. Thus, a direction for improving the thermal stress resistance of TEMs is presented.

  13. High Power Modulator/regulators for neutral beam sources

    International Nuclear Information System (INIS)

    Lawson, J.Q.; Deitz, A.

    1975-01-01

    PPPL has recently completed two new Modulator/Regulators for neutral injection sources used on the ATC machine and is constructing four new ones for use with sources on the PLT machine. The ATC modulator uses the well proven 4CX35,000C tetrode as the main switch tube, while the PLT modulators will be using the new but significantly higher powered X-2170 tetrodes. Some interesting circuit and manufacturing techniques are discussed

  14. Dispersed solar thermal generation employing parabolic dish-electric transport with field modulated generator systems

    Science.gov (United States)

    Ramakumar, R.; Bahrami, K.

    1981-01-01

    This paper discusses the application of field modulated generator systems (FMGS) to dispersed solar-thermal-electric generation from a parabolic dish field with electric transport. Each solar generation unit is rated at 15 kWe and the power generated by an array of such units is electrically collected for insertion into an existing utility grid. Such an approach appears to be most suitable when the heat engine rotational speeds are high (greater than 6000 r/min) and, in particular, if they are operated in the variable speed mode and if utility-grade a.c. is required for direct insertion into the grid without an intermediate electric energy storage and reconversion system. Predictions of overall efficiencies based on conservative efficiency figures for the FMGS are in the range of 25 per cent and should be encouraging to those involved in the development of cost-effective dispersed solar thermal power systems.

  15. French studies on the thermal effluents of electric power plants

    International Nuclear Information System (INIS)

    Dezes-Cadiere, H.

    1976-01-01

    This report presents a synthesis of studies made in France in the thermal effluent field: thermal power plant cooling systems, transfer and dispersion of thermal effluents in the receptive media, effects of thermal effluents on water physicochemistry and biochemistry, effects of thermal effluents on aquatic ecosystems, and, possibilities of waste heat recovery with the view of utilization in agriculture, aquaculture and district heating. A catalogue of French organizations working or having data on thermal effluents is presented, as also an alphabetical list of the contacted persons. A bibliography of French documents concerning the previously mentioned studies is finally given (193 refs.) [fr

  16. Applicability of advanced automotive heat engines to solar thermal power

    Science.gov (United States)

    Beremand, D. G.; Evans, D. G.; Alger, D. L.

    The requirements of a solar thermal power system are reviewed and compared with the predicted characteristics of automobile engines under development. A good match is found in terms of power level and efficiency when the automobile engines, designed for maximum powers of 65-100 kW (87 to 133 hp) are operated to the nominal 20-40 kW electric output requirement of the solar thermal application. At these reduced power levels it appears that the automotive gas turbine and Stirling engines have the potential to deliver the 40+ percent efficiency goal of the solar thermal program.

  17. Troubleshooting of Modulator DC power supply at KOMAC

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae Seong; Kim, Han Sung; Kwon, Hyeok Jung; Kim, Seong Gu; Kim, Dae Il; Lee, Seok Geun; Kim, Jae Ha; Seol, Kyeong Tae; Cho, Yong Sub [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The process of solving problems to operate the 2nd converter modulator will be introduced. Also, the PSpice simulation result about the 12-pulse rectifier will be compared with the measurement result. KOMAC (KOrea Multi-purpose Accelerator Complex) has four HVCMs (High Voltage Converter Modulator) which are the power source of nine klystrons. Four HVCMs are already operated since 2013 for operating the 100 MeV linear proton accelerator at KOMAC. This HVCM system includes the 12-pulse rectifier (ac-dc), capacitors bank (dc-link, Pos, Neg) and converter modulator (dc-dc). Especially, the 12-pulse rectifier system receives the power from the utility and converts 3,300 ac voltage to 2,200 dc voltage for supplying the dc power to the capacitors bank. This rectifier system used twelve thyristors for the rectification and applied RC snubber networks to protect the semiconductor switches (thyristors). Since the 2nd modulator dc power supply has troubled, the troubleshooting process conducted by the staves of KOMAC. It takes 3 months to solve the problems because it is not easy to find the faulty wiring. Nevertheless, our staves found the faulty point with a hope to operate the modulator system and the PSpice simulation helps to solve the problems. Using PSpice which is tool for simulating the circuit, the dc power supply abnormal phenomenon was simulated exactly. After corrected the faulty wiring, the modulator dc power supply operated.

  18. Electro-thermal Modeling of Modern Power Devices for Studying Abnormal Operating Conditions

    DEFF Research Database (Denmark)

    Wu, Rui

    in industrial power electronic systems in the range above 10 kW. The failure of IGBTs can be generally classified as catastrophic failures and wear out failures. A wear out failure is mainly induced by accumulated degradation with time, while a catastrophic failure is triggered by a single-event abnormal....... The objective of this project has been to model and predict the electro-thermal behavior of IGBT power modules under abnormal conditions, especially short circuits. A thorough investigation on catastrophic failure modes and mechanisms of modern power semiconductor devices, including IGBTs and power diodes, has...

  19. High-Temperature Air-Cooled Power Electronics Thermal Design: Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Waye, Scot [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-08-01

    Power electronics that use high-temperature devices pose a challenge for thermal management. With the devices running at higher temperatures and having a smaller footprint, the heat fluxes increase from previous power electronic designs. This project overview presents an approach to examine and design thermal management strategies through cooling technologies to keep devices within temperature limits, dissipate the heat generated by the devices and protect electrical interconnects and other components for inverter, converter, and charger applications. This analysis, validation, and demonstration intends to take a multi-scale approach over the device, module, and system levels to reduce size, weight, and cost.

  20. Power Inverter Topologies for Photovoltaic Modules - A Review

    DEFF Research Database (Denmark)

    Kjær, Søren Bækhøj; Pedersen, John Kim; Blaabjerg, Frede

    2002-01-01

    This review-paper focuses on the latest development of inverters for photovoltaic AC-Modules. The power range for these inverters is usually within 90 Watt to 500 Watt, which covers the most commercial photovoltaic-modules. Self-commutated inverters have replaced the grid-commutated ones. The same...... is true for the bulky low-frequency transformers versus the high-frequency transformers, which are used to adapt the voltage level. The AC-Module provides a modular design and a flexible behaviour in various grid conditions. It hereby opens the market for photovoltaic-power for everyone at a low cost due...

  1. Thermal resistance matrix representation of thermal effects and thermal design in multi-finger power heterojunction bipolar transistors

    Institute of Scientific and Technical Information of China (English)

    Jin Dong-Yue; Zhang Wan-Rong; Chen Liang; Fu Qiang; Xiao Ying; Wang Ren-Qing; Zhao Xin

    2011-01-01

    The thermal resistance matrix including self-heating thermal resistance and thermal coupling resistance is presented to describe the thermal effects of multi-finger power heterojunction bipolar transistors. The dependence of thermal resistance matrix on finger spacing is also investigated. It is shown that both self-heating thermal resistance and thermal coupling resistance are lowered by increasing the finger spacing, in which the downward dissipated heat path is widened and the heat flow from adjacent fingers is effectively suppressed. The decrease of self-heating thermal resistance and thermal coupling resistance is helpful for improving the thermal stability of power devices. Furthermore, with the aid of the thermal resistance matrix, a 10-finger power heterojunction bipolar transistor (HBT) with non-uniform finger spacing is designed for high thermal stability. The optimized structure can effectively lower the peak temperature while maintaining a uniformity of the temperature profile at various biases and thus the device effectively may operate at a higher power level.

  2. Safe affordable fission engine (SAFE 30) module conductivity test thermal model correlation

    International Nuclear Information System (INIS)

    Roman, Jose

    2001-01-01

    The SAFE 30 is a simple, robust space fission power system that is comprised of several independent modules. Each module contains 4 fuel tubes bonded to a central heatpipe. Fission energy is conducted from the fuel tubes to the heatpipe, which in turn transfers the energy to a power conversion system. This paper benchmarks a thermal model of the SAFE 30 with actual test data from simulated SAFE 30 module tests. Two 'dummy' SAFE 30 modules were fabricated - each consisted of 4 1-inch dia. tubes (simulating the fuel tubes) bonded to a central '1' dia. tube (simulating the heatpipe). In the first module the fuel tubes were simply brazed to the heatpipe along the line of contact (leaving void space in the interstices), and in the second module the tubes and heatpipe were brazed via tri-cusps that completely fill the interstices between the tubes. In these tests, fission energy is simulated by placing resistance heaters within each of the 4 fuel tubes. The tests were conducted in a vacuum chamber in 4 configurations: tri-cusps filled with and without an outer insulation wrap, and no tri-cusps with and without an outer insulation wrap. The baseline SAFE 30 configuration uses the brazed tri-cusps. During the tests, the power applied to the heaters was varied in a stepwise fashion, until a steady-state temperature profile was reached. These temperature levels varied between 773 K and 1073 K. To benchmark the thermal model, the input energy and chamber surface temperature were used as boundary conditions for the model. The analytical results from the nodes at the same location as the test thermocouples were plotted again test data to determinate the accuracy of the analysis. The unknown variables on the analysis are the radiation emissivity of the pipe and chamber and the radiation view factor between the module and the chamber. A correlation was determined using a parametric analysis by varying the surface emissivity and view factor until a good match was reached. This

  3. ESTIMATION OF THERMAL PARAMETERS OF POWER BIPOLAR TRANSISTORS BY THE METHOD OF THERMAL RELAXATION DIFFERENTIAL SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    V. S. Niss

    2015-01-01

    Full Text Available Thermal performance of electronic devices determines the stability and reliability of the equipment. This leads to the need for a detailed thermal analysis of semiconductor devices. The goal of the work is evaluation of thermal parameters of high-power bipolar transistors in plastic packages TO-252 and TO-126 by a method of thermal relaxation differential spectrometry. Thermal constants of device elements and distribution structure of thermal resistance defined as discrete and continuous spectra using previously developed relaxation impedance spectrometer. Continuous spectrum, based on higher-order derivatives of the dynamic thermal impedance, follows the model of Foster, and discrete to model of Cauer. The structure of sample thermal resistance is presented in the form of siх-chain electro-thermal RC model. Analysis of the heat flow spreading in the studied structures is carried out on the basis of the concept of thermal diffusivity. For transistor structures the area and distribution of the heat flow cross-section are determined. On the basis of the measurements the thermal parameters of high-power bipolar transistors is evaluated, in particular, the structure of their thermal resistance. For all of the measured samples is obtained that the thermal resistance of the layer planting crystal makes a defining contribution to the internal thermal resistance of transistors. In the transition layer at the border of semiconductor-solder the thermal resistance increases due to changes in the mechanism of heat transfer. Defects in this area in the form of delamination of solder, voids and cracks lead to additional growth of thermal resistance caused by the reduction of the active square of the transition layer. Method of thermal relaxation differential spectrometry allows effectively control the distribution of heat flow in high-power semiconductor devices, which is important for improving the design, improve the quality of landing crystals of power

  4. Dimmable electronic ballasts by variable power density modulation technique

    Science.gov (United States)

    Borekci, Selim; Kesler, Selami

    2014-11-01

    Dimming can be accomplished commonly by switching frequency and pulse density modulation techniques and a variable inductor. In this study, a variable power density modulation (VPDM) control technique is proposed for dimming applications. A fluorescent lamp is operated in several states to meet the desired lamp power in a modulation period. The proposed technique has the same advantages of magnetic dimming topologies have. In addition, a unique and flexible control technique can be achieved. A prototype dimmable electronic ballast is built and experiments related to it have been conducted. As a result, a 36WT8 fluorescent lamp can be driven for a desired lamp power from several alternatives without modulating the switching frequency.

  5. Thermal Hydraulic Analysis of K-DEMO Single Blanket Module for Preliminary Accident Analysis using MELCOR

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Bo; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of)

    2016-05-15

    To develop the Korean fusion commercial reactor, preliminary design concept for K-DEMO (Korean fusion demonstration reactor) has been announced by NFRI (National Fusion Research Institute). This pre-conceptual study of K-DEMO has been introduced to identify technical details of a fusion power plant for the future commercialization of fusion reactor in Korea. Before this consideration, to build the K-DEMO, accident analysis is essential. Since the Fukushima accident, which is severe accident from unexpected disaster, safety analysis of nuclear power plant has become important. The safety analysis of both fission and fusion reactors is deemed crucial in demonstrating the low radiological effect of these reactors on the environment, during severe accidents. A risk analysis of K-DEMO should be performed, as a prerequisite for the construction of a fusion reactor. In this research, thermal-hydraulic analysis of single blanket module of K-DEMO is conducted for preliminary accident analysis for K-DEMO. Further study about effect of flow distributer is conducted. The normal K-DEMO operation condition is applied to the boundary condition and simulated to verify the material temperature limit using MELCOR. MELCOR is fully integrated, relatively fast-running code developed by Sandia National Laboratories. MELCOR had been used for Light Water Reactors and fusion reactor version of MELCOR was developed for ITER accident analysis. This study shows the result of thermal-hydraulic simulation of single blanket module with MELCOR which is severe accident code for nuclear fusion safety analysis. The difference of mass flow rate for each coolant channel with or without flow distributer is presented. With flow distributer, advantage of broadening temperature gradient in the K-DEMO blanket module and increase mass flow toward first wall is obtained. This can enhance the safety of K-DEMO blanket module. Most 13 .deg. C temperature difference in blanket module is obtained.

  6. Effects of thermal cycling on aluminum metallization of power diodes

    DEFF Research Database (Denmark)

    Brincker, Mads; Pedersen, Kristian Bonderup; Kristensen, Peter Kjær

    2015-01-01

    Reconstruction of aluminum metallization on top of power electronic chips is a well-known wear out phenomenon under power cycling conditions. However, the origins of reconstruction are still under discussion. In the current study, a method for carrying out passive thermal cycling of power diodes...

  7. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats ?

    OpenAIRE

    Mohammed, Haitham S.; Fahmy, Heba M.; Radwan, Nasr M.; Elsayed, Anwar A.

    2012-01-01

    In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day). EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) revealed that the REM sleep is more susc...

  8. Low-power DAC-less PAM-4 transmitter using a cascaded microring modulator.

    Science.gov (United States)

    Dubé-Demers, Raphaël; LaRochelle, Sophie; Shi, Wei

    2016-11-15

    Future super-computer interconnect systems and data centers request ultrahigh data rate links at low cost and power consumption, for which transmitters with a high level of integration and spectral efficient formats are key components. We report 60 Gb/s pulse-amplitude modulation (PAM-4) of an optical signal using a dual-microring silicon photonics circuit, making a low-power, digital-to-analog converter (DAC)-less PAM modulator. The power consumption is evaluated below 100 fJ/bit, including thermal adjustments. To the best of our knowledge, these results feature the lowest reported power consumption for PAM signaling in a DAC-less scheme for data rate beyond 40 Gb/s.

  9. Remotely powered and controlled EAPap actuator by amplitude modulated microwaves

    International Nuclear Information System (INIS)

    Yang, Sang Yeol; Mahadeva, Suresha K; Kim, Jaehwan

    2013-01-01

    This paper reports on a remotely powered and controlled Electro-Active Paper (EAPap) actuator without onboard controller using amplitude modulated microwaves. A rectenna is a key element for microwave power transmission that converts microwaves into dc power through coupling and rectification. In this study, the concept of a remotely controlled and powered EAPap actuator is proposed by means of modulating microwaves with a control signal and demodulating it through the rectenna rectification. This concept is applied to a robust EAPap actuator, namely cellulose–polypyrrole–ionic liquid (CPIL) EAPap. Details of fabrication and characterization of the rectenna and the CPIL-EAPap actuator are explained. Also, the charge accumulation problem of the actuator is explained and resolved by connecting an additional resistor. Since this idea can eliminate the onboard controller by supplying the operating signal through modulation, a compact and lightweight actuator can be achieved, which is useful for biomimetic robots and remotely driven actuators. (technical note)

  10. Japanese aquaculture with thermal water from power plants

    International Nuclear Information System (INIS)

    Kuroda, T.

    1977-01-01

    The present level of thermal aquaculture, utilizing thermal water which is waste cooling water from nuclear power plant, in Japan is reported. There are 13 major potential areas for thermal aquaculture in cooperation with conventional type thermal power plants, seven of which are actually operating. Aquaculture facilities of all these are on land, none in the sea. Of these seven centers, those that have already commercialized their nursery methods or are approaching that stage of research and development, are Tohoku Hatsuden Kogyo Ltd., Tsuruga Hama Land Ltd. and Kyushu Rinsan Ltd. Major problems faced specialists in Japanese thermal aquaculture are water temperature, water quality, radioactivity and costs. For keeping the water temperature constant all seasons, cooling or heating by natural sea water may be used. Even negligible amounts of radioactivity that nuclear power plants release into the sea will concentrate in the systems of marine life. A strict precautionary checking routine is used to detect radioactivity in marine life. (Kobatake, H.)

  11. Thermodynamic analysis of thermal efficiency and power of Minto engine

    International Nuclear Information System (INIS)

    He, Wei; Hou, Jingxin; Zhang, Yang; Ji, Jie

    2011-01-01

    Minto engine is a kind of liquid piston heat engine that operates on a small temperature gradient. But there is no power formula for it yet. And its thermal efficiency is low and formula sometimes is misused. In this paper, deriving the power formula and simplifying the thermal efficiency formula of Minto engine based on energy distribution analysis will be discussed. To improve the original Minto engine, a new design of improved Minto engine is proposed and thermal efficiency formula and power formula are also given. A computer program was developed to analyze thermal efficiency and power of original and improved Minto engines operating between low and high-temperature heat sources. The simulation results show that thermal efficiency of improved Minto engine can reach over 7% between 293.15 K and 353.15 K which is much higher than that of original one; the temperature difference between upper and lower containers is lower than half of that between low and high temperature of heat sources when the original Minto engines output the maximum power; on the contrary, it is higher in the improved Minto engines. -- Highlights: ► The thermal efficiency formula of Minto engine is simplified and the power formula is established. ► A high-powered design of improved Minto engine is proposed. ► A computer simulation program based on real operating environment is developed.

  12. Thermal design, analysis and comparison on three concepts of space solar power satellite

    Science.gov (United States)

    Yang, Chen; Hou, Xinbin; Wang, Li

    2017-08-01

    Space solar power satellites (SSPS) have been widely studied as systems for collecting solar energy in space and transmitting it wirelessly to earth. A previously designed planar SSPS concept collects solar power in two huge arrays and then transmits it through one side of the power-conduction joint to the antenna. However, the system's one group of power-conduction joints may induce a single point of failure. As an SSPS concept, the module symmetrical concentrator (MSC) architecture has many advantages. This architecture can help avoid the need for a large, potentially failure-prone conductive rotating joint and limit wiring mass. However, the thermal control system has severely restricted the rapid development of MSC, especially in the sandwich module. Because of the synchronous existence of five suns concentration and solar external heat flux, the sandwich module will have a very high temperature, which will surpass the permissible temperature of the solar cells. Recently, an alternate multi-rotary joints (MR) SSPS concept was designed by the China Academy of Space Technology (CAST). This system has multiple joints to avoid the problem of a single point of failure. Meanwhile, this concept has another advantage for reducing the high power and heat removal in joints. It is well known to us that, because of the huge external flux in SSPS, the thermal management sub-system is an important component that cannot be neglected. Based on the three SSPS concepts, this study investigated the thermal design and analysis of a 1-km, gigawatt-level transmitting antenna in SSPS. This study compares the thermal management sub-systems of power-conduction joints in planar and MR SSPS. Moreover, the study considers three classic thermal control architectures of the MSC's sandwich module: tile, step, and separation. The study also presents an elaborate parameter design, analysis and discussion of step architecture. Finally, the results show the thermal characteristics of each SSPS

  13. Thermal impact assessment of multi power plant operations on estuaries

    International Nuclear Information System (INIS)

    Eraslan, A.H.; Kim, K.H.; Harris, J.L.

    1977-01-01

    The assessment of the thermal impact of multi power plant operations on large estuaries requires careful consideration of the problems associated with: re-entrainment, re-circulation, thermal interaction, delay in the attainment of thermal equilibrium state, and uncertainty in specifying open boundaries and open boundary conditions of the regions, which are critically important in the analysis of the thermal conditions in receiving water bodies with tidal dominated, periodically reversing flow conditions. The results of an extensive study in the Hudson River at Indian Point, 42 miles upstream of the ocean end at the Battery, concluded that the tidal-transient, multi-dimensional discrete-element (UTA) thermal transport models (ESTONE, FLOTWO, TMPTWO computer codes) and the near-field far-field zone-matching methodology can be employed with a high degree of reliability in the assessment of the thermal impact of multi power plant operations on tidal dominated estuaries

  14. STUDIES ON IGBT MODULE TO IMPROVE THE RELIABILITY OF POWER ELECTRONIC SYSTEMS

    DEFF Research Database (Denmark)

    Choi, Uimin

    component level to converter level. It is divided into two main parts: the first part, which consists of Chapters 2 and 3, is reliability studies of the IGBT module regarding thermal stresses and the second part, composed of Chapters 4 and 5, discusses strategies to improve the reliability and availability...... are presented. Then, in Chapter 3, the effect of junction temperature swing duration t△Tj on the lifetime of the transfer molded Intelligent Power IGBT Module is investigated and modeled based on the power cycling test results. In addition, the physics-of-failure analysis results of the tested modules...... are presented. Finally, in Chapters 4 and 5, open-circuit fault detection and fault-tolerant control methods are proposed for two kinds of neutral-point clamped three-level inverters T-type and NPC inverters. One of main contributions in this project is the development of an apparatus and methodology...

  15. Fracture mechanics in new designed power module under thermo-mechanical loads

    Directory of Open Access Journals (Sweden)

    Durand Camille

    2014-06-01

    Full Text Available Thermo-mechanically induced failure is a major reliability issue in the microelectronic industry. On this account, a new type of Assembly Interconnected Technology used to connect MOSFETs in power modules has been developed. The reliability is increased by using a copper clip soldered on the top side of the chip, avoiding the use of aluminium wire bonds, often responsible for the failure of the device. Thus the new designed MOSFET package does not follow the same failure mechanisms as standard modules. Thermal and power cycling tests were performed on these new packages and resulting failures were analyzed. Thermo-mechanical simulations including cracks in the aluminium metallization and intermetallics (IMC were performed using Finite Element Analysis in order to better understand crack propagation and module behaviour.

  16. Small Spacecraft Integrated Power System with Active Thermal Control

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop an integrated power generation and energy storage system with an active thermal management system. Carbon fiber solar panels will contain...

  17. Fast thermal cycling-enhanced electromigration in power metallization

    NARCIS (Netherlands)

    Nguyen, Van Hieu; Salm, Cora; Krabbenborg, B.H.; Krabbenborg, B.H.; Bisschop, J.; Mouthaan, A.J.; Kuper, F.G.

    Fast thermal nterconnects used in power ICs are susceptible to short circuit failure due to a combination of fast thermal cycling and electromigration stresses. In this paper, we present a study of electromigration-induced extrusion short-circuit failure in a standard two level metallization

  18. Several aspects of the effect of nuclear power engineering and thermal power engineering on the environment

    Energy Technology Data Exchange (ETDEWEB)

    Malenchenko, A F

    1979-01-01

    A survey is made of the comparative effect of nuclear power engineering and thermal power engineering on environment and man. The most significant approaches to solution of radio-ecological problems of APS are found.

  19. Nuclear and thermal power plant power ramping capability

    International Nuclear Information System (INIS)

    Golovach, E.A.

    1983-01-01

    The possibilities of step power increase by NPP and TPP units under emergency conditions of power grids operation are considered. The data analysis has shown that power units ramping capability with WWER-440, WWER-1000 and RBMK-1000 reactors is higher than that of 300 MW power units on fossil fuel, at the initial time interval (0-30 s). These NPP power units satisfy as to ramping capability the energy system requirements. Higher NPP power units ramping capability is explained by the fact that relative pressure before turbine valves is decreased less than in straight-through boilers while the steam volumes time constant of steam separator-superheaters is less than that of intermediate superheatings. Higher power unit ramping capability with WWER-440 and RBMK-1000 reactors as compared with the WWER-1000 reactor is pointed out as well as the increase of WWER-1000 power unit capability using high-speed turbines

  20. Process control and monitoring system: Thermal Power Plant Gacko

    International Nuclear Information System (INIS)

    Jeremovic, Dragan; Skoko, Maksim; Gjokanovic, Zdravko

    2004-01-01

    DCS Ovation system, manufactured by Westinghouse, USA, is described in this paper. Emphasize on concept of realization and basic characteristic in Thermal Power Plant Gacko is given in this paper. The most important, noticed by now, comparative effects and performances of new monitoring and control system according to classical monitoring and control system of 300 MW units Thermal Power Plant Gacko in Gacko, are given in the conclusion. (Author)

  1. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats☆

    Science.gov (United States)

    Mohammed, Haitham S.; Fahmy, Heba M.; Radwan, Nasr M.; Elsayed, Anwar A.

    2012-01-01

    In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day). EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR) than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested. PMID:25685416

  2. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats

    Directory of Open Access Journals (Sweden)

    Haitham S. Mohammed

    2013-03-01

    Full Text Available In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day. EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS and rapid eye movement sleep (REM sleep revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested.

  3. Solid state modulator for klystron power supply XFEL TDS INJ

    Science.gov (United States)

    Zavadtsev, A. A.; Zavadtsev, D. A.; Zybin, D. A.; Churanov, D. V.; Shemarykin, P. V.

    2016-09-01

    The transverse deflecting system XFEL TDS INJ for European X-ray Free Electron Laser includes power supply for the CPI VKS-8262HS klystron. It has been designed for pulse high-voltage, cathode heating, solenoid and klystron ion pump. The klystron power supply includes solid state modulator, pulse transformer, controlled power supply for cathode heating and commercial power supplies for solenoid and ion pump. Main parameters of the modulator are 110 kV of peak voltage, 72 A peak current, and pulse length up to 6 μs. The klystron power supply has been developed, designed, manufactured, tuned, tested and installed in the XFEL building. All designed parameters are satisfied.

  4. Thermal Impact Analysis of Circulating Current in High Power Modular Online Uninterruptible Power Supplies Application

    DEFF Research Database (Denmark)

    Zhang, Chi; Guerrero, Josep M.; Vasquez, Juan Carlos

    2015-01-01

    In a modular uninterruptible power supplies (UPS), each DC/AC module was designed to work in a circular way considering the reliability and power stress issues of the whole system. Thus unsynchronized PWMs will occur if any of the DC/AC modules is plugged in or out of the system at any time...

  5. Photovoltaic Array Space Power flight experiment plus diagnostics (PASP+) modules

    International Nuclear Information System (INIS)

    Cooley, W.T.; Adams, S.F.; Reinhardt, K.C.; Piszczor, M.F.

    1992-01-01

    The Photovoltaic Array Space Power Plus Diagnostics flight experiment (PASP+) subsumes twelve solar array modules which represent the state of the art in the space photovoltaic array industry. Each of the twelve modules individually feature specific photovoltaic technologies such as advanced semiconductor materials, multi-bandgap structures, lightweight array designs, advanced interconnect technologies, or concentrator array designs. This paper will describe each module in detail including the configuration, components, materials, anticipated on orbit performance, and some of the aspects of each array technology. The layout of each module and the photovoltaic cell or array cross section will be presented graphically. A discussion on the environmental constraints and materials selection will be included as well as a delineation of the differences between the modules and the baseline array configuration in its intended application

  6. CHP in Switzerland from 1990 to 1998. Thermal power generation including combined heat and power

    International Nuclear Information System (INIS)

    Kaufmann, U.

    1999-01-01

    The results of a study on thermal power generation in Switzerland show that combined heat and power (CHP) systems have grown rapidly. Statistics are presented on the development of CHP-based power and also on thermal power stations without waste heat usage. Figures are given for gas and steam turbine installations, combined gas and steam turbine stations and motor-driven CHP units. Power production is categorised, separating small and large (over 1 Megawatt electrical) power generation facilities. On-site, distributed power generation at consumers' premises and the geographical distribution of plant is described

  7. Power module for an experimental picosatellite Cubesat type

    Directory of Open Access Journals (Sweden)

    Javier Castro Avellaneda

    2016-06-01

    Full Text Available This article describes a power module for picosatellite following CubeSat standard requirements [1,2,3,13]. The Power Module project is developed in four phases: study, design, implementation and testing. In the study phase of the theoretical framework and preliminary designs made in the Universidad Distrital [4,5] and other CubeSat developed in the world is reviewed, also investigates existing technologies and components in the market and its affordability. The design phase involves analysis of the system and using a computer program designed to generate the necessary hardware. The ultimate goal is to obtain a functional power module and work in space environment conditions in which the picosatellite keep his focus on an application in telemedicine, with a payload that would become the telecommunications system mission.

  8. Energy saving and consumption reducing evaluation of thermal power plant

    Science.gov (United States)

    Tan, Xiu; Han, Miaomiao

    2018-03-01

    At present, energy saving and consumption reduction require energy saving and consumption reduction measures for thermal power plant, establishing an evaluation system for energy conservation and consumption reduction is instructive for the whole energy saving work of thermal power plant. By analysing the existing evaluation system of energy conservation and consumption reduction, this paper points out that in addition to the technical indicators of power plant, market activities should also be introduced in the evaluation of energy saving and consumption reduction in power plant. Ttherefore, a new evaluation index of energy saving and consumption reduction is set up and the example power plant is calculated in this paper. Rresults show that after introducing the new evaluation index of energy saving and consumption reduction, the energy saving effect of the power plant can be judged more comprehensively, so as to better guide the work of energy saving and consumption reduction in power plant.

  9. Ocean thermal energy conversion (OTEC) power system development. Preliminary design report, Appendices, Part 1 (Final)

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC demonstration plant. In turn, this demonstration plant is to demonstrate, by 1984, the operation and performance of an Ocean Thermal Power Plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the demonstration plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibilty studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report contains appendices on the developed computer models, water system dynamic studies, miscellaneous performance analysis, materials and processes, detailed equipment lists, turbine design studies, tube cleaner design, ammonia leak detection, and heat exchanger design supporting data. (WHK)

  10. LH power deposition and CD efficiency studies by application of modulated power at JET

    International Nuclear Information System (INIS)

    Kirov, K.K.; Baranov, Yu.; Mailloux, J.; Mayoral, M.-L.; Nave, M.F.F.; Ongena, J.

    2010-01-01

    The lower hybrid (LH) power deposition and the current drive (CD) efficiency were assessed by the application of modulated LH power. Density and magnetic field scans were performed and the response of the electron temperature provided by the available electron cyclotron emission diagnostic was investigated by means of fast Fourier transform analysis. An innovative technique based on a comparison between modelled and experimental data was developed and used in the study. The LH waves are absorbed by fast electrons with energies of a few times the thermal one, causing a modification in the electron distribution function (EDF) by creating a plateau in the parallel direction. The phase of the temperature perturbations, φ, as well as the ratio between the amplitudes of the third and the main harmonics, δT e3 /δT e1 , are found to be strongly affected by the plateau of the EDF as the broader the plateau the larger |φ|, (φ e3 /δT e1 are. Transport and Fokker-Planck modelling was used to support this conclusion as well as to interpret the experimental data and hence to assess the LHCD efficiency and deposition profile. The results from the analysis are consistent with broad off-axis LH power deposition profile. For densities between 1 x 10 19 and 4 x 10 19 m -3 , which is the accessibility limit at the highest magnetic field discharges, a gradual shift of the maximum of the power deposition to the periphery and a degradation of the CD efficiency was observed.

  11. Power trade: A mean to replace thermal to hydro power

    Energy Technology Data Exchange (ETDEWEB)

    Viladrich, Christian; Brun, Pierre; Pereira, Alice; Moustafa, Fatma

    2010-09-15

    In the framework of the Eastern Nile Power Trade Program Study a comprehensive generation and transmission expansion plan was established for Egypt, Ethiopia, and Sudan. The results show that an interconnection between these countries is profitable and has a positive impact on CO2 savings. A common development of power system and a power market can promote the regional cooperation to use the Nile waters for the benefit of the entire region.

  12. Power Electronics Thermal Management Research: Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilberto [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-19

    The objective for this project is to develop thermal management strategies to enable efficient and high-temperature wide-bandgap (WBG)-based power electronic systems (e.g., emerging inverter and DC-DC converter). Reliable WBG devices are capable of operating at elevated temperatures (≥ 175 °Celsius). However, packaging WBG devices within an automotive inverter and operating them at higher junction temperatures will expose other system components (e.g., capacitors and electrical boards) to temperatures that may exceed their safe operating limits. This creates challenges for thermal management and reliability. In this project, system-level thermal analyses are conducted to determine the effect of elevated device temperatures on inverter components. Thermal modeling work is then conducted to evaluate various thermal management strategies that will enable the use of highly efficient WBG devices with automotive power electronic systems.

  13. Power MOSFET Thermal Instability Operation Characterization Support

    Science.gov (United States)

    Shue, John L.; Leidecker, Henning

    2010-01-01

    Metal-oxide semiconductor field-effect transistors (MOSFETs) are used extensively in flight hardware and ground support equipment. In the quest for faster switching times and lower "on resistance," the MOSFETs designed from 1998 to the present have achieved most of their intended goals. In the quest for lower on resistance and higher switching speeds, the designs now being produced allow the charge-carrier dominated region (once small and outside of the area of concern) to become important and inside the safe operating area (SOA). The charge-carrier dominated region allows more current to flow as the temperature increases. The higher temperatures produce more current resulting in the beginning of thermal runaway. Thermal runaway is a problem affecting a wide range of modern MOSFETs from more than one manufacturer. This report contains information on MOSFET failures, their causes and test results and information dissemination.

  14. Rankine-Brayton engine powered solar thermal aircraft

    Science.gov (United States)

    Bennett, Charles L [Livermore, CA

    2009-12-29

    A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

  15. Rankline-Brayton engine powered solar thermal aircraft

    Science.gov (United States)

    Bennett, Charles L [Livermore, CA

    2012-03-13

    A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

  16. Japanese aquaculture: use of thermal water from power plant

    International Nuclear Information System (INIS)

    Kuroda, Takeya

    1983-01-01

    There is some merit of thermal water from power plants in the effect to marine life. Since 1963, the research and development on the aquaculture using this warm water have been carried out at some twenty power plants, seven nuclear and thirteen thermal, some of which are now in the commercial stage. These fish farming projects are operated variously from seed to adult fish production. They can also be classified as land and sea facilities, conforming to the characteristics of the respective sea areas. The current situation in this field and the future prospect are described: thermal aquaculture including seed production and adult fish farming; the projects in nuclear and thermal power plants, respectively; future problems in the facilities, breeding environment and marine life for cultivation. (Mori, K.)

  17. Efficiency improvement of thermal coal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hourfar, D. [VEBA Kraftwerke Ruhr Ag, Gelsenkirchen (Germany)

    1996-12-31

    The discussion concerning an increase of the natural greenhouse effect by anthropogenic changes in the composition of the atmosphere has increased over the past years. The greenhouse effect has become an issue of worldwide debate. Carbon dioxide is the most serious emission of the greenhouse gases. Fossil-fired power plants have in the recent past been responsible for almost 30 % of the total CO{sub 2} emissions in Germany. Against this background the paper will describe the present development of CO{sub 2} emissions from power stations and present actual and future opportunities for CO{sub 2} reduction. The significance attached to hard coal as one of today`s prime sources of energy with the largest reserves worldwide, and, consequently, its importance for use in power generation, is certain to increase in the years to come. The further development of conventional power plant technology, therefore, is vital, and must be carried out on the basis of proven operational experience. The main incentive behind the development work completed so far has been, and continues to be, the achievement of cost reductions and environmental benefits in the generation of electricity by increasing plant efficiency, and this means that, in both the short and the long term, power plants with improved conventional technology will be used for environmentally acceptable coal-fired power generation.

  18. Hot Thermal Storage in a Variable Power, Renewable Energy System

    Science.gov (United States)

    2014-06-01

    where cost effective, increase the utilization of distributed electric power generation through wind, solar, geothermal , and biomass renewable...characteristics and may not necessarily be available in all cases. Types of direct heat energy systems include solar thermal, waste heat, and geothermal ...of super capacitor energy storage system in microgrid,” in International Conference on Sustainable Power Generation and Supply, Janjing, China

  19. Long term energy performance analysis of Egbin thermal power ...

    African Journals Online (AJOL)

    This study is aimed at providing an energy performance analysis of Egbin thermal power plant. The plant operates on Regenerative Rankine cycle with steam as its working fluid .The model equations were formulated based on some performance parameters used in power plant analysis. The considered criteria were plant ...

  20. Solar Probe Plus MAG Sensor Thermal Design for Low Heater Power and Extreme Thermal Environment

    Science.gov (United States)

    Choi, Michael K.

    2015-01-01

    The heater power available for the Solar Probe Plus FIELDS MAG sensor is less than half of the heritage value for other missions. Nominally the MAG sensors are in the spacecraft's umbra. In the worst hot case, approximately 200 spacecraft communication downlinks, up to 10 hours each, are required at 0.7 AU. These downlinks require the spacecraft to slew 45 deg. about the Y-axis, exposing the MAG sensors and boom to sunlight. This paper presents the thermal design to meet the MAG sensor thermal requirements in the extreme thermal environment and with low heater power. A thermal balance test on the MAG sensor engineering model has verified the thermal design and correlated the thermal model for flight temperature predictions.

  1. Outgassing studies of lower hybrid antenna module during CW high RF power injection

    International Nuclear Information System (INIS)

    Goniche, M.; Brossaud, J.; Berger-By, G.; Bibet, Ph.; Poli, S.; Rey, G.; Tonon, G.; Seki, M.; Obara, K.; Maebara, S.; Ikeda, Y.; Imai, T.; Nagashima, T.

    1994-01-01

    Outgassing, induced by very long RF waves injection (up to 6000s) at high power density, is studied with a module, able to be used for a lower hybrid frequency antenna. A large outgassing data base is provided by 75 shots cumulating 27 hours of RF injection. Outgassing rate is documented after different thermal pre-treatments, and in various conditions of cooling, RF power level. Relevant parameters are identified and values of outgassing rates are given in order to design pumping system for a large antenna. (author) 4 refs.; 7 figs.; 1 tab

  2. Effects of Auxiliary-Source Connection in Multichip Power Module

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Wang, Xiongfei

    2017-01-01

    the power loop and the gate loop like how the Kelvin-source connection does, owing to their involvement in the loop of the power source current. Three effects of the auxiliary-source connections are then analyzed, which are 1) the common source stray inductance reduction, 2) the transient drain......Auxiliary-source bond wires and connections are widely used in power modules with paralleled MOSFETs or IGBTs. This paper investigates the operation mechanism of the auxiliary-source connections in multichip power modules. It reveals that the auxiliary-source connections cannot fully decouple......-source current imbalance mitigation, and 3) the influence on the steady-state current distribution. Lastly, simulations and experimental results validate the theoretical analysis....

  3. Upgrading of electrostatic precipitators in old thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Gurumurthy, H V

    1987-02-01

    Indian thermal power stations installed in the 60's and earlier had dust collectors whose efficiency was well below the acceptable level of emission under the Air (Prevention and Control of Pollution) Act 1981. This necessitates the need for higher efficiency dust collectors to be installed in old thermal power stations. Further, the poor quality of the coal being received at power stations presently causes severe environmental pollution in and around the plant. This paper deals with the retrofitting of electrostatic precipitators in existing units and the problems encountered in executing the same.

  4. Thermal energy storage for CSP (Concentrating Solar Power

    Directory of Open Access Journals (Sweden)

    Py Xavier

    2017-01-01

    Full Text Available The major advantage of concentrating solar power before photovoltaic is the possibility to store thermal energy at large scale allowing dispatchability. Then, only CSP solar power plants including thermal storage can be operated 24 h/day using exclusively the solar resource. Nevertheless, due to a too low availability in mined nitrate salts, the actual mature technology of the two tanks molten salts cannot be applied to achieve the expected international share in the power production for 2050. Then alternative storage materials are under studies such as natural rocks and recycled ceramics made from industrial wastes. The present paper is a review of those alternative approaches.

  5. Thermal energy storage for CSP (Concentrating Solar Power)

    Science.gov (United States)

    Py, Xavier; Sadiki, Najim; Olives, Régis; Goetz, Vincent; Falcoz, Quentin

    2017-07-01

    The major advantage of concentrating solar power before photovoltaic is the possibility to store thermal energy at large scale allowing dispatchability. Then, only CSP solar power plants including thermal storage can be operated 24 h/day using exclusively the solar resource. Nevertheless, due to a too low availability in mined nitrate salts, the actual mature technology of the two tanks molten salts cannot be applied to achieve the expected international share in the power production for 2050. Then alternative storage materials are under studies such as natural rocks and recycled ceramics made from industrial wastes. The present paper is a review of those alternative approaches.

  6. Investigation of solar photovoltaic module power output by various models

    International Nuclear Information System (INIS)

    Jakhrani, A.Q.; Othman, A.K.; Rigit, A.R.H.; Baini, R.

    2012-01-01

    This paper aims to investigate the power output of a solar photovoltaic module by various models and to formulate a suitable model for predicting the performance of solar photovoltaic modules. The model was used to correct the configurations of solar photovoltaic systems for sustainable power supply. Different types of models namely the efficiency, power, fill factor and current-voltage characteristic curve models have been reviewed. It was found that the examined models predicted a 40% yield of the rated power in cloudy weather conditions and up to 80% in clear skies. The models performed well in terms of electrical efficiency in cloudy days if the influence of low irradiance were incorporated. Both analytical and numerical methods were employed in the formulation of improved model which gave +- 2% error when compared with the rated power output of solar photovoltaic module. The proposed model is more practical in terms of number of variables used and acceptable performance in humid atmospheres. Therefore, it could be useful for the estimation of power output of the solar photovoltaic systems in Sarawak region. (author)

  7. Techno-economic design optimization of solar thermal power plants

    OpenAIRE

    Morin, G.

    2011-01-01

    A holistic view is essential in the engineering of technical systems. This thesis presents an integrative approach for designing solar thermal power plants. The methodology is based on a techno-economic plant model and a powerful optimization algorithm. Typically, contemporary design methods treat technical and economic parameters and sub-systems separately, making it difficult or even impossible to realize the full optimization potential of power plant systems. The approach presented here ov...

  8. Endomorphism Algebras of Tensor Powers of Modules for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Therese Søby

    We determine the ring structure of the endomorphism algebra of certain tensor powers of modules for the quantum group of sl2 in the case where the quantum parameter is allowed to be a root of unity. In this case there exists -- under a suitable localization of our ground ring -- a surjection from...... the group algebra of the braid group to the endomorphism algebra of any tensor power of the Weyl module with highest weight 2. We take a first step towards determining the kernel of this map by reformulating well-known results on the semisimplicity of the Birman-Murakami-Wenzl algebra in terms of the order...... of the quantum parameter. Before we arrive at these main results, we investigate the structure of the endomorphism algebra of the tensor square of any Weyl module....

  9. Digital Processor Module Reliability Analysis of Nuclear Power Plant

    International Nuclear Information System (INIS)

    Lee, Sang Yong; Jung, Jae Hyun; Kim, Jae Ho; Kim, Sung Hun

    2005-01-01

    The system used in plant, military equipment, satellite, etc. consists of many electronic parts as control module, which requires relatively high reliability than other commercial electronic products. Specially, Nuclear power plant related to the radiation safety requires high safety and reliability, so most parts apply to Military-Standard level. Reliability prediction method provides the rational basis of system designs and also provides the safety significance of system operations. Thus various reliability prediction tools have been developed in recent decades, among of them, the MI-HDBK-217 method has been widely used as a powerful tool for the prediction. In this work, It is explained that reliability analysis work for Digital Processor Module (DPM, control module of SMART) is performed by Parts Stress Method based on MIL-HDBK-217F NOTICE2. We are using the Relex 7.6 of Relex software corporation, because reliability analysis process requires enormous part libraries and data for failure rate calculation

  10. Advanced power cycling test for power module with on-line on-state VCE measurement

    DEFF Research Database (Denmark)

    Choi, Ui-min; Trintis, Ionut; Blaabjerg, Frede

    2015-01-01

    module. The proposed concept can perform various stress conditions which is valid in a real mission profile and it is using a real power converter application with small loss. The concept of the proposed test setup is first presented. Then, the on-line on-state collector-emitter voltage VCE measurement......Recent research has made an effort to improve the reliability of power electronic systems to comply with more stringent constraints on cost, safety, predicted lifetime and availability in many applications. For this, studies about failure mechanisms of power electronic components and lifetime...... estimation of power semiconductor devices and capacitors have been done. Accelerated power cycling test is one of the common tests to assess the power device module and develop the lifetime model considering the physics of failure. In this paper, a new advanced power cycling test setup is proposed for power...

  11. Application of Discontinuous PWM Modulation in Active Power Filters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Rodriguez, Pedro

    2008-01-01

    Classical discontinuous pulsewidth modulations (DPWMs) may not be efficiently applied in active power filters (APFs), because it is hard to predict the peak values of the inverter current, and consequently it is difficult to calculate the position of the clamped interval, that minimizes...

  12. Decision on thermal power plant can be taken this spring

    International Nuclear Information System (INIS)

    Haga, I.

    1978-01-01

    Towards the end of the 1960s it appeared that nuclear power would be the natural successor to hydroelectric power, as the latter became less attractive for further exploitation, reinforced by environmentalist opposition to several proposed hydroelectric schemes. Conventional thermal power was also considered, but one proposed stand-by plant was rejected in 1971 largely because of environmental considerations. Preliminary planning and PR information on nuclear power in the early 1970s aroused considerable opposition and a governmental commission was appointed in 1975-6 to evaluate the question of reactor safety and transport and disposal of radioactive waste, to report in 1978. It is therefore not possible to count on nuclear power as a supplement until the end of the 1980s at the earliest. Gas-fired thermal power is environmentally attractive, but at present no gas fields have been found which make this economic. Oil-fired power is quite feasible, but no political decision has yet been taken. Coal fuel, based on the Spitzbergen mines has recently become more interesting, and small power plants for the extreme north of Norway are under consideration. Finally it is pointed out that nuclear power is safer than generally assumed while fluidised bed combustion of coal in a combined steam-gas turbine plant will lead to very high thermal efficiencies. (JIW)

  13. Water cooling thermal power measurement in a vacuum diffusion pump

    Directory of Open Access Journals (Sweden)

    Luís Henrique Cardozo Amorin

    2012-04-01

    Full Text Available Diffusion vacuum pumps are used both in industry and in laboratory science for high vacuum production. For its operation they must be refrigerated, and it is done by circulating water in open circuit. Considering that, vacuum systems stays operating by hours, the water consumption may be avoided if the diffusion vacuum pumps refrigeration were done in closed circuit. However, it is necessary to know the diffusion vacuum pump thermal power (the heat transferred to circulate water by time units to implement one of these and get in the refrigeration system dimension. In this paper the diffusion vacuum pump thermal power was obtained by measuring water flow and temperature variation and was calculated through the heat quantity variation equation time function. The thermal power value was 935,6 W, that is 397 W smaller and 35 W bigger than, respectively, the maximum and minimum diffusion pump thermal power suggested by its operation manual. This procedure have been shown useful to precisely determine the diffusion pump thermal power or of any other system that needs to be refrigerated in water closed circuit.

  14. Comprehensive physical analysis of bond wire interfaces in power modules

    DEFF Research Database (Denmark)

    Popok, Vladimir; Pedersen, Kristian Bonderup; Kristensen, Peter Kjær

    2016-01-01

    causing failures. In this paper we present a review on the set of our experimental and theoretical studies allowing comprehensive physical analysis of changes in materials under active power cycling with focus on bond wire interfaces and thin metallisation layers. The developed electro-thermal and thermo...

  15. Thermal Design of Power Electronic Circuits

    CERN Document Server

    Künzi, R.

    2015-06-15

    The heart of every switched mode converter consists of several switching semiconductor elements. Due to their non-ideal behaviour there are ON state and switching losses heating up the silicon chip. That heat must effectively be transferred to the environment in order to prevent overheating or even destruction of the element. For a cost-effective design, the semiconductors should be operated close to their thermal limits. Unfortunately the chip temperature cannot be measured directly. Therefore a detailed understanding of how losses arise, including their quantitative estimation, is required. Furthermore, the heat paths to the environment must be understood in detail. This paper describes the main issues of loss generation and its transfer to the environment and how it can be estimated by the help of datasheets and/or experiments.

  16. Cosmic microwave background power asymmetry from non-Gaussian modulation.

    Science.gov (United States)

    Schmidt, Fabian; Hui, Lam

    2013-01-04

    Non-Gaussianity in the inflationary perturbations can couple observable scales to modes of much longer wavelength (even superhorizon), leaving as a signature a large-angle modulation of the observed cosmic microwave background power spectrum. This provides an alternative origin for a power asymmetry that is otherwise often ascribed to a breaking of statistical isotropy. The non-Gaussian modulation effect can be significant even for typical ~10(-5) perturbations while respecting current constraints on non-Gaussianity if the squeezed limit of the bispectrum is sufficiently infrared divergent. Just such a strongly infrared-divergent bispectrum has been claimed for inflation models with a non-Bunch-Davies initial state, for instance. Upper limits on the observed cosmic microwave background power asymmetry place stringent constraints on the duration of inflation in such models.

  17. Behaviour at thermal ageing of power cable components through penetrations

    International Nuclear Information System (INIS)

    Puiu, D.; Gyongyosi, T.; Dinu, E.

    2009-01-01

    The materials for electric insulation and exterior jackets of the power cables are formulated organic compounds. The environmental service conditions will induce chemical and/or physical processes at molecular level of the material; these processes are the ageing mechanisms. The power cables passing through penetrations lead to an increase of the rate of thermal ageing mechanisms, resulting in irreversible degradation of mechanical and electric properties of the organic compounds and of the functional properties of the cable. The paper presents the results of the laboratory tests when the real environmental service conditions for penetration are simulated, the comparison with the results of the thermal computation of the power cables heating and the evaluation of the influence of temperature increase of the power cable components on the cable lifetime. For the particular case of a power cable with PVC insulation, we estimated a lifetime decrease about seven years as referred to lifetime of about 30 years for operation in air. (authors)

  18. Power Control and Monitoring Requirements for Thermal Vacuum/Thermal Balance Testing of the MAP Observatory

    Science.gov (United States)

    Johnson, Chris; Hinkle, R. Kenneth (Technical Monitor)

    2002-01-01

    The specific heater control requirements for the thermal vacuum and thermal balance testing of the Microwave Anisotropy Probe (MAP) Observatory at the Goddard Space Flight Center (GSFC) in Greenbelt, Maryland are described. The testing was conducted in the 10m wide x 18.3m high Space Environment Simulator (SES) Thermal Vacuum Facility. The MAP thermal testing required accurate quantification of spacecraft and fixture power levels while minimizing heater electrical emissions. The special requirements of the MAP test necessitated construction of five (5) new heater racks.

  19. Thermal-hydraulics for space power, propulsion, and thermal management system design

    International Nuclear Information System (INIS)

    Krotiuk, W.J.

    1990-01-01

    The present volume discusses thermal-hydraulic aspects of current space projects, Space Station thermal management systems, the thermal design of the Space Station Free-Flying Platforms, the SP-100 Space Reactor Power System, advanced multi-MW space nuclear power concepts, chemical and electric propulsion systems, and such aspects of the Space Station two-phase thermal management system as its mechanical pumped loop and its capillary pumped loop's supporting technology. Also discussed are the startup thaw concept for the SP-100 Space Reactor Power System, calculational methods and experimental data for microgravity conditions, an isothermal gas-liquid flow at reduced gravity, low-gravity flow boiling, computations of Space Shuttle high pressure cryogenic turbopump ball bearing two-phase coolant flow, and reduced-gravity condensation

  20. Simulation and experiment of thermal energy management with phase change material for ageing LiFePO4 power battery

    International Nuclear Information System (INIS)

    Rao Zhonghao; Wang Shuangfeng; Zhang Guoqing

    2011-01-01

    Highlights: → We study the thermal energy management performance of ageing LiFePO 4 power battery. → 3-D modules of single cell and battery pack are formulated according to the experimental results. → Thermal resistance in the battery cell leaded to an inevitable temperature difference. → It is necessary to improve the thermal conductivity and lower the melting point of phase change material. → Thermal conductivity of phase change material and battery exist an effective proportion. - Abstract: Thermal energy management performance of ageing commercial rectangular LiFePO 4 power batteries using phase change material (PCM) and thermal behavior related to thermal conductivity between the PCM and the cell are discussed in this paper. The heat sources are simplified according to the experimental results of the cells discharged at 35 A (∼5 C). 3-D modules of a single cell and battery pack are formulated, respectively. The results show that the thermal resistance in the cell leads to an inevitable temperature difference. It is necessary to improve the thermal conductivity and to lower the melting point of the PCM for heat transfer enhancement. The PCM with a melting point lower than 45 deg. C will be more effective for heat dissipation, with a desired maximum temperature below 50 deg. C. The temperature difference in the whole unit before PCM melting will be decreased significantly. In addition, a proper k PCM :k c is necessary for a well designed battery thermal energy management system.

  1. Power Cycling Test Method for Reliability Assessment of Power Device Modules in Respect to Temperature Stress

    DEFF Research Database (Denmark)

    Choi, Ui-Min; Blaabjerg, Frede; Jørgensen, Søren

    2018-01-01

    Power cycling test is one of the important tasks to investigate the reliability performance of power device modules in respect to temperature stress. From this, it is able to predict the lifetime of a component in power converters. In this paper, representative power cycling test circuits......, measurement circuits of wear-out failure indicators as well as measurement strategies for different power cycling test circuits are discussed in order to provide the current state of knowledge of this topic by organizing and evaluating current literature. In the first section of this paper, the structure...... of a conventional power device module and its related wear-out failure mechanisms with degradation indicators are discussed. Then, representative power cycling test circuits are introduced. Furthermore, on-state collector-emitter voltage (VCE ON) and forward voltage (VF) measurement circuits for wear-out condition...

  2. Using thermal power plants waste for building materials

    Science.gov (United States)

    Feduik, R. S.; Smoliakov, A. K.; Timokhin, R. A.; Batarshin, V. O.; Yevdokimova, Yu G.

    2017-10-01

    The recycled use of thermal power plants (TPPs) wastes in the building materials production is formulated. The possibility of using of TPPs fly ash as part of the cement composite binder for concrete is assessed. The results of X-ray diffraction and differential thermal analysis as well as and materials photomicrographs are presented. It was revealed that the fly ash of TPPs of Russian Primorsky Krai is suitable for use as a filler in cement binding based on its chemical composition.

  3. Conceptual design and analysis of a Dish-Rankine solar thermal power system

    Science.gov (United States)

    Pons, R. L.

    1980-08-01

    A Point Focusing Distributed Receiver (PFDR) solar thermal electric system which employs small Organic Rankine Cycle (ORC) engines is examined with reference to its projected technical/economic performance. With mass-produced power modules (about 100,000 per year), the projected life-cycle energy cost for an optimized no-storage system is estimated at 67 mills/kWh (Levelized Busbar Energy Cost) without the need for advanced development of any of its components. At moderate production rates (about 50 MWe/yr) system energy costs are competitive with conventional power generation systems in special remote-site types of applications.

  4. Advanced concrete structures for thermal power plants

    International Nuclear Information System (INIS)

    Zerna, W.

    1982-01-01

    The author begins with an overview on the various types of power plants depending on the fuel used in them and then in particular deals with the reinforced concrete structures. Especially for reactor buildings and prestressed concrete pressure vessels concrete is the appropriate material. The methods of construction are described as a function of load and operation. Safety requirements brought new load types for such structures as e.g. airplane crash, internal pressure caused by pipe rupture. Dimensioning is done by means of nonlinear dynamical methods of calculation accounting for plasticizing. These methods are explained. Further the constructional principles of high natural-draft cooling towers are mentioned. (orig.) [de

  5. Power-law modulation of the scalar power spectrum from a heavy field with a monomial potential

    Science.gov (United States)

    Huang, Qing-Guo; Pi, Shi

    2018-04-01

    The effects of heavy fields modulate the scalar power spectrum during inflation. We analytically calculate the modulations of the scalar power spectrum from a heavy field with a separable monomial potential, i.e. V(phi)~ phin. In general the modulation is characterized by a power-law oscillation which is reduced to the logarithmic oscillation in the case of n=2.

  6. High RF power test of a CFC antenna module for lower hybrid current drive

    International Nuclear Information System (INIS)

    Maebara, S.; Seki, M.; Ikeda, Y.; Kiyono, K.; Suganuma, K.; Imai, T.; Goniche, M.; Bibet, Ph.; Brossaud, J.; Cano, V.; Kazarian-Vibert, F.; Froissard, P.; Rey, G.

    1998-01-01

    A mock-up of a 3.7 GHz Lower Hybrid Current Drive (LHCD) antenna module was fabricated from Carbon Fibre Composite (CFC) for the development of heat resistive low Z front facing the plasma. This 2 divided waveguide module is made from CFC plates and rods which are Cu-plated to reduce the RF losses. The withstand-voltage, the RF properties and the outgassing rates for long pulses and high RF power were tested at the Lower Hybrid test bed facility of Cadarache. A reference module made from Dispersion Strengthened Copper (DSC) was also fabricated. After the short pulse conditioning, long pulses with a power density ranging between 50 and 150 MW/m 2 were performed with no breakdowns on the CFC module. It was also checked that the highest power density, up to 150 MW/m 2 , could be transmitted when the waveguides are filled with H2 at a pressure of 5 x 10 -2 Pa. During a long pulse, the power reflection coefficient remains low in the 0.8-1.3 % range and no significant change in the reflection coefficient is measured after the thermal cycling provided by the long pulse operation. From thermocouple measurements, RF losses of the copper coated CFC and the DSC modules were compared. No significant differences were measured. From pressure measurements, it was found that the outgassing rate of Cu-plated CFC is about 6-7 times larger than of DSC at 300 deg.C. It is concluded that a CFC module is an attractive candidate for the hardening of the tip of the LHCD antenna. (author)

  7. Real Time Monitoring and Wear Out of Power Modules

    DEFF Research Database (Denmark)

    Ghimire, Pramod

    the expected lifetime of converters. Real time monitoring of power modules is very important together with a smart control and a driving technique in a converter. This ensures to operate the device within a safe operating area and also to protect from a catastrophic failure. Furthermore, the inherent physical...... and in a mission-profile oriented advanced power cycling test. The measurement technique is implemented in a full scale converter under field oriented test conditions. Initially, a real time measurement technique and it's implementation in a converter are introduced. A full scale converter is also used......Power electronic devices have a wide range of applications from very low to high power at constantly varying load conditions. Irrespective of the harsh operating loads, including both internal and external, an improvement in a performance such as efficiency, power density, reliability and cost...

  8. PULSE MODULATION POWER AMPLIFIER WITH ENHANCED CASCADE CONTROL METHOD

    DEFF Research Database (Denmark)

    1998-01-01

    a single local feedback path A (7) with a lowpass characteristic and local forward blocks B¿1? or B (3, 4). The leads to a much improved system with a very low sensitivity to errors in the switching power stage. In the second preferred embodiment of the invention the control structure is extended...... and feedback path A to determine stable self-oscillating conditions. An implemented 250W example MECC digital power amplifier has proven superior performance in terms of audio performance (0.005 % distortion, 115 dB dynamic range) and efficiency (92 %).......A digital switching power amplifier with Multivariable Enhanced Cascade Controlled (MECC) includes a modulator, a switching power stage and a low pass filter. In the first preferred embodiment an enhanced cascade control structure local to the switching power stage is added, characterised by having...

  9. Source driven breeding thermal power reactors

    International Nuclear Information System (INIS)

    Greenspan, E.; Ben-Gurion Univ. of the Negev, Beersheba

    1978-03-01

    The feasibility of fusion devices operating in the semi-catalyzed deuterium (SCD) mode and of high energy proton accelerators to provide the neutron sources for driving subcritical breeding light water power reactors is assessed. The assessment is done by studying the energy balance of the resulting source driven light water reactors (SDLWR) and comparing it with the energy balance of the reference light water hybrid reactors (LWHR) driven by a D-T neutron source (DT-LWHR). The conditions the non-DT neutron sources should satisfy in order to make the SDLWR viable power reactors are identified. It is found that in order for a SCD-LWHR to have the same overall efficiency as a DT-LWHR, the fusion energy gain of the SCD device should be at least one half that the DT device. The efficienct of ADLWRs using uranium targets is comparable with that of DT-LWHRs having a fusion energy gain of unity. Advantages and disadvantages of the DT-LWHR, SCD-LWHR and ADLWR are discussed. (aurthor)

  10. Characterization of a photovoltaic-thermal module for Fresnel linear concentrator

    International Nuclear Information System (INIS)

    Chemisana, D.; Ibanez, M.; Rosell, J.I.

    2011-01-01

    Highlights: → A combined domed Fresnel lens - CPC PVT system is designed and characterized. → Electrical and thermal experiments have been performed. → CFD analysis has been used to determine thermal characteristic dimensionless numbers. - Abstract: An advanced solar unit is designed to match the needs of building integration and concentrating photovoltaic/thermal generation. The unit proposed accurately combines three elements: a domed linear Fresnel lens as primary concentrator, a compound parabolic reflector as secondary concentrator and a photovoltaic-thermal module. In this work the photovoltaic-thermal generator is built, analysed and characterized. Models for the electrical and thermal behaviour of the module are developed and validated experimentally. Applying a thermal resistances approach the results from both models are combined. Finally, efficiency electrical and thermal curves are derived from theoretical analysis showing good agreement with experimental measurements.

  11. Thermal Analysis of a Power Conditioning Unit for a Howitzer

    Science.gov (United States)

    2009-08-01

    contact resistance Interface ( mA2 -K / W) AL-PCB 0.000389 AL-AL (thermal grease) 0.000083 AL-power chips 0.003891 AL-power chips (thermal grease...1120 W/ mA2 . Figure 3 shows the view of the box that the source of the solar radiation sees. The inside of the box is cluttered with cables, wiring, and...temperature (130°F) and a conservative convective heat transfer coefficient (5 W/ mA2 ) to all of the outer surfaces. These outer surfaces would

  12. Design considerations for RF power amplifiers demonstrated through a GSM/EDGE power amplifier module

    NARCIS (Netherlands)

    Baltus, P.G.M.; Bezooijen, van A.; Huijsing, J.H.; Steyaert, M.; Roermund, van A.H.M.

    2002-01-01

    This paper describes the design considerations for RF power amplifiers in general, including trends in systems, linearity and efficiency, the PA environment, implementation is sues and technology. As an example a triple-band (900/1800/1900MHz) dual mode (GSMIEdge) power amplifier module is described

  13. Solar thermal power plants simulation using the TRNSYS software

    Energy Technology Data Exchange (ETDEWEB)

    Popel, O.S.; Frid, S.E.; Shpilrain, E.E. [Institute for High Temperatures, Russian Academy of Sciences (IVTAN), Moscow (Russian Federation)

    1999-03-01

    The paper describes activity directed on the TRNSYS software application for mathematical simulation of solar thermal power plants. First stage of developments has been devoted to simulation and thermodynamic analysis of the Hybrid Solar-Fuel Thermal Power Plants (HSFTPP) with gas turbine installations. Three schemes of HSFTPP, namely: Gas Turbine Regenerative Cycle, Brayton Cycle with Steam Injection and Combined Brayton-Rankine Cycle,- have been assembled and tested under the TRNSYS. For this purpose 18 new models of the schemes components (gas and steam turbines, compressor, heat-exchangers, steam generator, solar receiver, condenser, controllers, etc) have been elaborated and incorporated into the TRNSYS library of 'standard' components. The authors do expect that this initiative and received results will stimulate experts involved in the mathematical simulation of solar thermal power plants to join the described activity to contribute to acceleration of development and expansion of 'Solar Thermal Power Plants' branch of the TRNSYS. The proposed approach could provide an appropriate basis for standardization of analysis, models and assumptions for well-founded comparison of different schemes of advanced solar power plants. (authors)

  14. Performance analysis of a lunar based solar thermal power system with regolith thermal storage

    International Nuclear Information System (INIS)

    Lu, Xiaochen; Ma, Rong; Wang, Chao; Yao, Wei

    2016-01-01

    The manned deep-space exploration is a hot topic of the current space activities. The continuous supply of thermal and electrical energy for the scientific equipment and human beings is a crucial issue for the lunar outposts. Since the night lasts for periods of about 350 h at most locations on the lunar surface, massive energy storage is required for continuous energy supply during the lengthy lunar night and the in-situ resource utilization is demanded. A lunar based solar thermal power system with regolith thermal storage is presented in this paper. The performance analysis is carried out by the finite-time thermodynamics to take into account major irreversible losses. The influences of some key design parameters are analyzed for system optimization. The analytical results shows that the lunar based solar thermal power system with regolith thermal storage can meet the requirement of the continuous energy supply for lunar outposts. - Highlights: • A lunar based solar thermal power system with regolith thermal storage is presented. • The performance analysis is carried out by the finite-time thermodynamics. • The influences of some key design parameters are analyzed.

  15. Possibilities for retrofitting of the existing thermal electric power plants using solar power technologies

    International Nuclear Information System (INIS)

    Matjanov, Erkinjon K.; Abduganieva, Farogat A.; Aminov, Zarif Z.

    2012-01-01

    Full text: Total installed electric power output of the existing thermal electric power plants in Uzbekistan is reaches 12 GW. Thermal electric power plants, working on organic fuel, produce around 88 % of the electricity in the country. The emission coefficient of CO 2 gases is 620 gram/kwph. Average electric efficiency of the thermal electric power plants is 32.1 %. The mentioned above data certifies, that the existing thermal electric power plants of Uzbekistan are physically and morally aged and they need to be retrofitted. Retrofitting of the existing thermal electric power plants can be done by several ways such as via including gas turbine toppings, by using solar technologies, etc. Solar thermal power is a relatively new technology which has already shown its enormous promise. With few environmental impacts and a massive resource, it offers a comparable opportunity to the sunniest Uzbekistan. Solar thermal power uses direct sunlight, so it must be sited in regions with high direct solar radiation. In many regions, one square km of land is enough to generate as much as 100-120 GWh of electricity per year using the solar thermal technology. This is equivalent to the annual production of a 50 MW conventional coal or gas-fired mid-load power plant. Solar thermal power plants can be designed for solar-only or for hybrid operation. Producing electricity from the energy in the sun's rays is a straightforward process: direct solar radiation can be concentrated and collected by a range of Concentrating Solar Power technologies to provide medium- to high temperature heat. This heat is then used to operate a conventional power cycle, for example through a steam turbine or a Stirling engine. Solar heat collected during the day can also be stored in liquid or solid media such as molten salts, ceramics, concrete or, in the future, phase-changing salt mixtures. At night, it can be extracted from the storage medium thereby continuing turbine operation. Currently, the

  16. Study and Handling Methods of Power IGBT Module Failures in Power Electronic Converter Systems

    DEFF Research Database (Denmark)

    Choi, Uimin; Blaabjerg, Frede; Lee, Kyo-Beum

    2015-01-01

    Power electronics plays an important role in a wide range of applications in order to achieve high efficiency and performance. Increasing efforts are being made to improve the reliability of power electronics systems to ensure compliance with more stringent constraints on cost, safety......, and availability in different applications. This paper presents an overview of the major failure mechanisms of IGBT modules and their handling methods in power converter systems improving reliability. The major failure mechanisms of IGBT modules are presented first, and methods for predicting lifetime...... and estimating the junction temperature of IGBT modules are then discussed. Subsequently, different methods for detecting open- and short-circuit faults are presented. Finally, fault-tolerant strategies for improving the reliability of power electronic systems under field operation are explained and compared...

  17. Finite Element Model for Thermal-Structural analysis of CLIC Lab Module type 0#2

    CERN Document Server

    Moilanen, Antti; Vamvakas, Alex; Vainola, Jukka Ilmari; Doebert, Steffen

    2017-01-01

    Temperature changes lead to unwanted thermo-mechanical deformations in the components of the Compact Linear Collider (CLIC) module. There are several sources and sinks of heat around the CLIC two-beam module. Heat is generated in the components that produce, transfer, and extract radio frequency (RF) power. Excess heat is removed from the components by cooling water as well as dissipated to air by convection from the outer surfaces of the components. The ambient temperature might also vary along the tunnel during the operation of CLIC. Due to tight assembling and alignment tolerances, it is necessary to minimize the thermo-mechanical deformations in the components. In this paper, the steps of thermal-structural Finite Element Analysis (FEA) of CLIC lab module type 0#2 are described from geometry model simplification to setting up the simulation. The description is accompanied by useful hints for CATIA and ANSYS users performing similar modelling tasks. A reliable computer simulation is important for studying ...

  18. Ecological safety of thermal power industry and investments

    International Nuclear Information System (INIS)

    Glebov, V.P.

    1995-01-01

    Evaluation of ecological safety of domestic fossil fuel thermal power industry is given in comparison with foreign one. Ways of solving ecological problems are considered. They are based on introduction of new technologies, providing decrease of ecological effect, on development of effective ash-and sulfur-trapping, nitrogen purification equipment, on production of ecologically improved fuel. The necessity of investments to power industry is noted

  19. FGD Franchising Pilot Project of Thermal Power Plants

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    According to the national policy on enhancing environmental protection,the five major power generation companies are required to carry out flue gas desulphurization(FGD) franchising pilot project in thermal power plants.This paper introduces the development of this pilot project,including the foundation,purpose,objects,demands and procedures.It also discusses some main problems encountered during implementation,involving the understanding,legislation,financing,taxation,pricing and management of franchise.At...

  20. Estimating the power efficiency of the thermal power plant modernization by using combined-cycle technologies

    International Nuclear Information System (INIS)

    Hovhannisyan, L.S.; Harutyunyan, N.R.

    2013-01-01

    The power efficiency of the thermal power plant (TPP) modernization by using combined-cycle technologies is introduced. It is shown that it is possible to achieve the greatest decrease in the specific fuel consumption at modernizing the TPP at the expense of introducing progressive 'know-how' of the electric power generation: for TPP on gas, it is combined-cycle, gas-turbine superstructures of steam-power plants and gas-turbines with heat utilization

  1. Maximum power analysis of photovoltaic module in Ramadi city

    Energy Technology Data Exchange (ETDEWEB)

    Shahatha Salim, Majid; Mohammed Najim, Jassim [College of Science, University of Anbar (Iraq); Mohammed Salih, Salih [Renewable Energy Research Center, University of Anbar (Iraq)

    2013-07-01

    Performance of photovoltaic (PV) module is greatly dependent on the solar irradiance, operating temperature, and shading. Solar irradiance can have a significant impact on power output of PV module and energy yield. In this paper, a maximum PV power which can be obtain in Ramadi city (100km west of Baghdad) is practically analyzed. The analysis is based on real irradiance values obtained as the first time by using Soly2 sun tracker device. Proper and adequate information on solar radiation and its components at a given location is very essential in the design of solar energy systems. The solar irradiance data in Ramadi city were analyzed based on the first three months of 2013. The solar irradiance data are measured on earth's surface in the campus area of Anbar University. Actual average data readings were taken from the data logger of sun tracker system, which sets to save the average readings for each two minutes and based on reading in each one second. The data are analyzed from January to the end of March-2013. Maximum daily readings and monthly average readings of solar irradiance have been analyzed to optimize the output of photovoltaic solar modules. The results show that the system sizing of PV can be reduced by 12.5% if a tracking system is used instead of fixed orientation of PV modules.

  2. Application of CPLD in CSR power supply control module

    International Nuclear Information System (INIS)

    Liu Caihong; Guo Yuhui; Chinese Academy of Sciences, Beijing; Jing Lan; Qiao Weimin

    2005-01-01

    A realization of Single Chip Microcomputer peripheral interface in HIRFL-CSR power supply control module based on CPLD is presented in the paper. It integrates flip-latch, coding unit, data bus, frequency division unit, logical compare unit, counter and logic circuit into a single CPLD chip, and dramatically decreases the area of PCB and increase system reliability, at the same time the whole system's flexibility has been evidently improved because of the CPLD's in-system programmable characteristics. (authors)

  3. Thermal effects on metabolic activities of thermophilic microorganisms from the thermal discharge point of Tuticorin thermal power plant area

    International Nuclear Information System (INIS)

    Muthukkannan, N.; Murugesan, A.G.

    2002-01-01

    Metabolic activities of thermophilic microorganisms isolated from the thermal water discharge point at Tuticorin thermal power station were studied by growing the microorganisms in sterile medium and at various temperature regimes of 25, 35, 45, 55 and 65degC. The optimum temperature for the growth of the bacterium isolated from the thermal power plant station was 45 degC and beyond 65 degC the growth was gradually decreased. The bacteria isolated from open sea water were mesophiles with their growth optimum at 35 degC and microbes inhabiting the thermal discharge area were thermopiles as they were tolerant even at 55 degC. The amylase production, carbohydrate metabolism and lactose fermentation activities were optimum at 45 degC. At 25 degC and beyond 65 degC biochemical activities of the organisms were inhibited to a greater extent. (author)

  4. Choosing Actuators for Automatic Control Systems of Thermal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Gorbunov, A. I., E-mail: gor@tornado.nsk.ru [JSC “Tornado Modular Systems” (Russian Federation); Serdyukov, O. V. [Siberian Branch of the Russian Academy of Sciences, Institute of Automation and Electrometry (Russian Federation)

    2015-03-15

    Two types of actuators for automatic control systems of thermal power plants are analyzed: (i) pulse-controlled actuator and (ii) analog-controlled actuator with positioning function. The actuators are compared in terms of control circuit, control accuracy, reliability, and cost.

  5. Mathematical Safety Assessment Approaches for Thermal Power Plants

    Directory of Open Access Journals (Sweden)

    Zong-Xiao Yang

    2014-01-01

    Full Text Available How to use system analysis methods to identify the hazards in the industrialized process, working environment, and production management for complex industrial processes, such as thermal power plants, is one of the challenges in the systems engineering. A mathematical system safety assessment model is proposed for thermal power plants in this paper by integrating fuzzy analytical hierarchy process, set pair analysis, and system functionality analysis. In the basis of those, the key factors influencing the thermal power plant safety are analyzed. The influence factors are determined based on fuzzy analytical hierarchy process. The connection degree among the factors is obtained by set pair analysis. The system safety preponderant function is constructed through system functionality analysis for inherence properties and nonlinear influence. The decision analysis system is developed by using active server page technology, web resource integration, and cross-platform capabilities for applications to the industrialized process. The availability of proposed safety assessment approach is verified by using an actual thermal power plant, which has improved the enforceability and predictability in enterprise safety assessment.

  6. Prospects for solving environmental problems pertinent to thermal power stations

    Energy Technology Data Exchange (ETDEWEB)

    A.G. Tumanovskii; V.R. Kotler [OAO All-Russia Thermal Engineering Institute, Moscow (Russian Federation)

    2007-06-15

    Possible ways to protect the atmosphere and water basin against harmful emissions and effluent waters discharged from thermal power stations are considered. Data on the effectiveness of different methods for removing NOx, SO{sub 2}, and ash particles, as well as heavy metals and CO{sub 2}, from these emissions and discharges are presented.

  7. Experience of Milled Peat Burning at Thermal Electric Power Plant

    Directory of Open Access Journals (Sweden)

    G. I. Zhikhar

    2013-01-01

    Full Text Available The paper presents extensive knowledge and practical experience on burning of milled peat in the boilers of thermal electric power plants in Belarus and Russia. The accumulated experience can be used for solution of problems pertaining to substitution of some types of fuel imported to Belarus by milled peat which is extracted at many fuel effective peat enterprises of the Republic.

  8. Determination of reactor thermal power using a more accurate method

    International Nuclear Information System (INIS)

    Papuga, J.; Madron, F.; Pliska, J.

    2005-01-01

    Reactor thermal power is an important operational parameter in many respects such as nuclear safety, reactor physics or evaluation of turbine thermal performance. Thermal power of a pressurized water reactor is determined on the basis of the steam generator thermal balance. The balance can be made in several variants differing from one another by the selection of different measuring circuits whose data are used in the balancing. In principle, no one such variant gives the true value of the thermal power. Among the variant values, the one nearest to the unknown true value of reactor thermal power is probably the value calculated with the lowest uncertainty. The determination of such uncertainty is not easy and its value can make even several percent, which has significant economic consequences. This paper presents the method of data reconciliation and its application to the data of the third of Dukovany NPP. The data reconciliation method allows to exploit all the information which process data contain. It is based on the statistical adjustment of the redundant data in such a way that the adjusted data obey generally valid laws of nature (e.g. conservation laws). Mass and energy balances based on the data not yet reconciled do not obey those laws because of measurement errors. For data reconciliation in Dukovany, a detailed model of mass and energy flows describing the 3rd unit from steam generators to alternator and condenser was set up. Laws of mass and energy conservation and phase equilibrium in water-steam systems are thus fulfilled. Moreover, the user can model momentum balances in pipelines and create other equations, which are respected during calculation. The data reconciliation is done regularly for hourly averages (Authors)

  9. Thermal design of a modern, air-conditioned, single-floor, solar-powered desert house

    KAUST Repository

    Serag-Eldin, M. A.

    2011-12-01

    The paper presents a thermal analysis of a single-floor, solar-powered desert house. The house is air-conditioned and provides all modern comforts and facilities. Electrical power, which drives the entire energy system, is generated by roof-mounted photovoltaic modules. The modules are fixed on special cradles which fold at night to expose the roof to the night sky, thereby enhancing night-time cooling, which is substantial in the desert environment. A detailed dynamic heat transfer analysis is conducted for the building envelope, coupled with a solar radiation model. Application to a typical Middle-Eastern desert site reveals that indeed such a design is feasible with present-day technology; and should be even more attractive with future advances in technology. © 2011 Copyright Taylor and Francis Group, LLC.

  10. Aging precursors and degradation effects of SiC-MOSFET modules under highly accelerated power cycling conditions

    DEFF Research Database (Denmark)

    Luo, Haoze; Iannuzzo, Francesco; Blaabjerg, Frede

    2017-01-01

    A highly accelerated power cycling test platform using current source converter for SiC-MOSFET power modules is proposed. The control principles of delta and average junction temperatures are introduced. By using isolated thermal fibers, the junction temperature (Tj) variations can be monitored...... and compared. As a result, the effects of degradation on the static and dynamic characteristics during conventional operation are discussed. Finally, the research results can help examine the failure precursors and then estimate the remaining useful lifetime of SiC MOSFET modules....

  11. Load Frequency Control of AC Microgrid Interconnected Thermal Power System

    Science.gov (United States)

    Lal, Deepak Kumar; Barisal, Ajit Kumar

    2017-08-01

    In this paper, a microgrid (MG) power generation system is interconnected with a single area reheat thermal power system for load frequency control study. A new meta-heuristic optimization algorithm i.e. Moth-Flame Optimization (MFO) algorithm is applied to evaluate optimal gains of the fuzzy based proportional, integral and derivative (PID) controllers. The system dynamic performance is studied by comparing the results with MFO optimized classical PI/PID controllers. Also the system performance is investigated with fuzzy PID controller optimized by recently developed grey wolf optimizer (GWO) algorithm, which has proven its superiority over other previously developed algorithm in many interconnected power systems.

  12. Thermal Storage Power Balancing with Model Predictive Control

    DEFF Research Database (Denmark)

    Halvgaard, Rasmus; Poulsen, Niels Kjølstad; Madsen, Henrik

    2013-01-01

    The method described in this paper balances power production and consumption with a large number of thermal loads. Linear controllers are used for the loads to track a temperature set point, while Model Predictive Control (MPC) and model estimation of the load behavior are used for coordination....... The total power consumption of all loads is controlled indirectly through a real-time price. The MPC incorporates forecasts of the power production and disturbances that influence the loads, e.g. time-varying weather forecasts, in order to react ahead of time. A simulation scenario demonstrates...

  13. Heat engine development for solar thermal power systems

    Science.gov (United States)

    Pham, H. Q.; Jaffe, L. D.

    The parabolic dish solar collector systems for converting sunlight to electrical power through a heat engine will, require a small heat engine of high performance long lifetime to be competitive with conventional power systems. The most promising engine candidates are Stirling, high temperature Brayton, and combined cycle. Engines available in the current market today do not meet these requirements. The development of Stirling and high temperature Brayton for automotive applications was studied which utilizes much of the technology developed in this automotive program for solar power engines. The technical status of the engine candidates is reviewed and the components that may additional development to meet solar thermal system requirements are identified.

  14. A self-adaptive thermal switch array for rapid temperature stabilization under various thermal power inputs

    International Nuclear Information System (INIS)

    Geng, Xiaobao; Patel, Pragnesh; Narain, Amitabh; Meng, Dennis Desheng

    2011-01-01

    A self-adaptive thermal switch array (TSA) based on actuation by low-melting-point alloy droplets is reported to stabilize the temperature of a heat-generating microelectromechanical system (MEMS) device at a predetermined range (i.e. the optimal working temperature of the device) with neither a control circuit nor electrical power consumption. When the temperature is below this range, the TSA stays off and works as a thermal insulator. Therefore, the MEMS device can quickly heat itself up to its optimal working temperature during startup. Once this temperature is reached, TSA is automatically turned on to increase the thermal conductance, working as an effective thermal spreader. As a result, the MEMS device tends to stay at its optimal working temperature without complex thermal management components and the associated parasitic power loss. A prototype TSA was fabricated and characterized to prove the concept. The stabilization temperatures under various power inputs have been studied both experimentally and theoretically. Under the increment of power input from 3.8 to 5.8 W, the temperature of the device increased only by 2.5 °C due to the stabilization effect of TSA

  15. Thermal power terms in the Einstein-dilaton system

    International Nuclear Information System (INIS)

    Zuo, Fen

    2014-01-01

    We employ the gauge/string duality to study the thermal power terms of various thermodynamic quantities in gauge theories and the renormalized Polyakov loop above the deconfinement phase transition. We restrict ourselves to the five-dimensional Einstein gravity coupled to a single scalar, the dilaton. The asymptotic solutions of the system for a general dilaton potential are employed to study the power contributions of various quantities. If the dilaton is dual to the dimension-4 operator TrF μν 2 , no power corrections would be generated. Then the thermal quantities approach their asymptotic values much more quickly than those observed in lattice simulation. When the dimension of the dual operator is different from 4, various power terms are generated. The lowest power contributions to the thermal quantities are always quadratic in the dilaton, while that of the Polyakov loop is linear. As a result, the quadratic terms in inverse temperature for both the trace anomaly and the Polyakov loop, observed in lattice simulation, cannot be implemented consistently in the system. This is in accordance with the field theory expectation, where no gauge-invariant operator can accommodate such contributions. Two simple models, where the dilaton is dual to operators with different dimensions, are studied in detail to clarify the conclusion.

  16. Super thermal power plants and environment: a critical appraisal

    International Nuclear Information System (INIS)

    Sharma, A.K.

    1995-01-01

    This paper discusses the possible impact on the environment by the particulate matters, oxides of sulphur and nitrogen, trace metals and solid/liquid wastes, which are emitted during the combustion of coal in the super thermal power plants of National Thermal Power Corporation (NTPC). The coal consumed by these plants have sufficient sulphur content and ash. Of all the mineral in coal, pyrite is one of the most deleterious in combustion and a major source of oxide of sulphur pollution of the atmosphere. The impact of these on the terrestrial and aquatic environment in and around power plants and on region have been discussed. To arresting such contaminants, some remedial measures are suggested. (author). 14 refs., 1 fig., 3 tabs

  17. Beam-Forming Concentrating Solar Thermal Array Power Systems

    Science.gov (United States)

    Cwik, Thomas A. (Inventor); Dimotakis, Paul E. (Inventor); Hoppe, Daniel J. (Inventor)

    2016-01-01

    The present invention relates to concentrating solar-power systems and, more particularly, beam-forming concentrating solar thermal array power systems. A solar thermal array power system is provided, including a plurality of solar concentrators arranged in pods. Each solar concentrator includes a solar collector, one or more beam-forming elements, and one or more beam-steering elements. The solar collector is dimensioned to collect and divert incoming rays of sunlight. The beam-forming elements intercept the diverted rays of sunlight, and are shaped to concentrate the rays of sunlight into a beam. The steering elements are shaped, dimensioned, positioned, and/or oriented to deflect the beam toward a beam output path. The beams from the concentrators are converted to heat at a receiver, and the heat may be temporarily stored or directly used to generate electricity.

  18. Thermal effects in high average power optical parametric amplifiers.

    Science.gov (United States)

    Rothhardt, Jan; Demmler, Stefan; Hädrich, Steffen; Peschel, Thomas; Limpert, Jens; Tünnermann, Andreas

    2013-03-01

    Optical parametric amplifiers (OPAs) have the reputation of being average power scalable due to the instantaneous nature of the parametric process (zero quantum defect). This Letter reveals serious challenges originating from thermal load in the nonlinear crystal caused by absorption. We investigate these thermal effects in high average power OPAs based on beta barium borate. Absorption of both pump and idler waves is identified to contribute significantly to heating of the nonlinear crystal. A temperature increase of up to 148 K with respect to the environment is observed and mechanical tensile stress up to 40 MPa is found, indicating a high risk of crystal fracture under such conditions. By restricting the idler to a wavelength range far from absorption bands and removing the crystal coating we reduce the peak temperature and the resulting temperature gradient significantly. Guidelines for further power scaling of OPAs and other nonlinear devices are given.

  19. The THESEUS project -- 50 MWe solar thermal power for Crete

    Energy Technology Data Exchange (ETDEWEB)

    Schillig, F.; Geyer, M.; Kistner, R.; Aringhoff, R.; Nava, P.; Brakmann, G.

    1998-07-01

    A consortium of European industry, utilities and research institutions from Greece, Germany, Spain and Italy attempts to implement a 52 MWe solar thermal power plant with parabolic trough technology on the Greek island of Crete sponsored by the EU' s THERMIE program. The increased demand for electricity on the island, a consequence of the growing allurement of the island as a tourist resort, makes it necessary to expand the installed capacity on Crete during the next years. According to the capacity expansion plans of Greek' s utility PPC a 160 MWe heavy fuel-fired power plant complex--two 30 MWe diesel units and two 50 MWe steam turbine units--is foreseen to be built by the year 2002. In this paper a description of the technical, economical and environmental aspects of the THESEUS project is provided. Moreover a market entry strategy for solar thermal power generation is discussed.

  20. Reference reactor module for NASA's lunar surface fission power system

    International Nuclear Information System (INIS)

    Poston, David I.; Kapernick, Richard J.; Dixon, David D.; Werner, James; Qualls, Louis; Radel, Ross

    2009-01-01

    Surface fission power systems on the Moon and Mars may provide the first US application of fission reactor technology in space since 1965. The Affordable Fission Surface Power System (AFSPS) study was completed by NASA/DOE to determine the cost of a modest performance, low-technical risk surface power system. The AFSPS concept is now being further developed within the Fission Surface Power (FSP) Project, which is a near-term technology program to demonstrate system-level TRL-6 by 2013. This paper describes the reference FSP reactor module concept, which is designed to provide a net power of 40 kWe for 8 years on the lunar surface; note, the system has been designed with technologies that are fully compatible with a Martian surface application. The reactor concept uses stainless-steel based. UO 2 -fueled, pumped-NaK fission reactor coupled to free-piston Stirling converters. The reactor shielding approach utilizes both in-situ and launched shielding to keep the dose to astronauts much lower than the natural background radiation on the lunar surface. The ultimate goal of this work is to provide a 'workhorse' power system that NASA can utilize in near-term and future Lunar and Martian mission architectures, with the eventual capability to evolve to very high power, low mass systems, for either surface, deep space, and/or orbital missions.

  1. Thermally regenerative hydrogen/oxygen fuel cell power cycles

    Science.gov (United States)

    Morehouse, J. H.

    1986-01-01

    Two innovative thermodynamic power cycles are analytically examined for future engineering feasibility. The power cycles use a hydrogen-oxygen fuel cell for electrical energy production and use the thermal dissociation of water for regeneration of the hydrogen and oxygen. The TDS (thermal dissociation system) uses a thermal energy input at over 2000 K to thermally dissociate the water. The other cycle, the HTE (high temperature electrolyzer) system, dissociates the water using an electrolyzer operating at high temperature (1300 K) which receives its electrical energy from the fuel cell. The primary advantages of these cycles is that they are basically a no moving parts system, thus having the potential for long life and high reliability, and they have the potential for high thermal efficiency. Both cycles are shown to be classical heat engines with ideal efficiency close to Carnot cycle efficiency. The feasibility of constructing actual cycles is investigated by examining process irreversibilities and device efficiencies for the two types of cycles. The results show that while the processes and devices of the 2000 K TDS exceed current technology limits, the high temperature electrolyzer system appears to be a state-of-the-art technology development. The requirements for very high electrolyzer and fuel cell efficiencies are seen as determining the feasbility of the HTE system, and these high efficiency devices are currently being developed. It is concluded that a proof-of-concept HTE system experiment can and should be conducted.

  2. 'Crud' detection and evaluation during the Embalse nuclear power plant's thermal cycle for powers of 100%

    International Nuclear Information System (INIS)

    Fernandez, A.; Rosales, A.H.; Mura, V.R.; Sentupery, C.; Rascon, H.

    1987-01-01

    This paper describes the 'crud' measurements performed during the Embalse nuclear power plant's thermal cycle for a power of 100% (645 MWe) under different purification conditions. The aim of this work is to optimize the four steam generators' tube plate cleaning in function of the sweeping produced by their purification. (Author)

  3. Solar thermal power systems point-focusing thermal and electric applications projects. Volume 1: Executive summary

    Science.gov (United States)

    Marriott, A.

    1980-01-01

    The activities of the Point-Focusing Thermal and Electric Applications (PETEA) project for the fiscal year 1979 are summarized. The main thrust of the PFTEA Project, the small community solar thermal power experiment, was completed. Concept definition studies included a small central receiver approach, a point-focusing distributed receiver system with central power generation, and a point-focusing distributed receiver concept with distributed power generation. The first experiment in the Isolated Application Series was initiated. Planning for the third engineering experiment series, which addresses the industrial market sector, was also initiated. In addition to the experiment-related activities, several contracts to industry were let and studies were conducted to explore the market potential for point-focusing distributed receiver (PFDR) systems. System analysis studies were completed that looked at PFDR technology relative to other small power system technology candidates for the utility market sector.

  4. Thermal Management and Reliability of Power Electronics and Electric Machines

    Energy Technology Data Exchange (ETDEWEB)

    Narumanchi, Sreekant

    2016-08-03

    Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil -- by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, and in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines will be presented.

  5. Thermal Management and Reliability of Power Electronics and Electric Machines

    Energy Technology Data Exchange (ETDEWEB)

    Narumanchi, Sreekant

    2016-06-13

    Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil - by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, and in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines are presented.

  6. Thermo-economic analysis of Shiraz solar thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Yaghoubi, M. [Academy of Science, Tehran (Iran, Islamic Republic of); Mokhtari, A.; Hesami, R. [Shiraz Univ., Shiraz (Iran, Islamic Republic of). School of Engineering

    2007-07-01

    The Shiraz solar thermal power plant in Iran has 48 parabolic trough collectors (PTCs) which are used to heat the working oil. There is potential to significantly increase the performance and reduce the cost of PTC solar thermal electric technologies. Conventional energy analysis based on the first law of thermodynamics does qualitatively assess the various losses occurring in the components. Therefore, exergy analysis, based on the second law of thermodynamics, can be applied to better assess various losses quantitatively as well as qualitatively. This paper presented a newly developed exergy-economic model for the Shiraz solar thermal power plant. The objective was to find the minimum exergetic production cost (EPC), based on the second law of thermodynamics. The application of exergy-economic analysis includes the evaluation of utility supply costs for production plants, and the energy costs for process operations. The purpose of the analysis was to minimize the total operating costs of the solar thermal power plant by assuming a fixed rate of electricity production and process steam. 21 refs., 3 tabs., 8 figs.

  7. Design study on the efficiency of the thermal scheme of power unit of thermal power plants in hot climates

    Science.gov (United States)

    Sedlov, A.; Dorokhov, Y.; Rybakov, B.; Nenashev, A.

    2017-11-01

    At the stage of pre-proposals unit of the thermal power plants for regions with a hot climate requires a design study on the efficiency of possible options for the structure of the thermal circuit and a set of key parameters. In this paper, the thermal circuit of the condensing unit powerfully 350 MW. The main feature of the external conditions of thermal power plants in hot climates is the elevated temperature of cooling water of the turbine condensers. For example, in the Persian Gulf region as the cooling water is sea water. In the hot season of the year weighted average sea water temperature of 30.9 °C and during the cold season to 22.8 °C. From the turbine part of the steam is supplied to the distillation-desalination plant. In the hot season of the year heat scheme with pressure fresh pair of 23.54 MPa, temperature 570/560 °C and feed pump with electric drive (EDP) is characterized by a efficiency net of 0.25% higher than thermal schem with feed turbine pump (TDP). However, the supplied power unit with PED is less by 11.6 MW. Calculations of thermal schemes in all seasons of the year allowed us to determine the difference in the profit margin of units of the TDP and EDP. During the year the unit with the TDP provides the ability to obtain the profit margin by 1.55 million dollars more than the unit EDP. When using on the market subsidized price of electricity (Iran) marginal profit of a unit with TDP more at 7.25 million dollars.

  8. Beat the Deviations in Estimating Maximum Power of Thermoelectric Modules

    DEFF Research Database (Denmark)

    Gao, Junling; Chen, Min

    2013-01-01

    Under a certain temperature difference, the maximum power of a thermoelectric module can be estimated by the open-circuit voltage and the short-circuit current. In practical measurement, there exist two switch modes, either from open to short or from short to open, but the two modes can give...... different estimations on the maximum power. Using TEG-127-2.8-3.5-250 and TEG-127-1.4-1.6-250 as two examples, the difference is about 10%, leading to some deviations with the temperature change. This paper analyzes such differences by means of a nonlinear numerical model of thermoelectricity, and finds out...... that the main cause is the influence of various currents on the produced electromotive potential. A simple and effective calibration method is proposed to minimize the deviations in specifying the maximum power. Experimental results validate the method with improved estimation accuracy....

  9. Efficiency assessment and benchmarking of thermal power plants in India

    International Nuclear Information System (INIS)

    Shrivastava, Naveen; Sharma, Seema; Chauhan, Kavita

    2012-01-01

    Per capita consumption of electricity in India is many folds lesser than Canada, USA, Australia, Japan, Chaina and world average. Even though, total energy shortage and peaking shortage were recorded as 11.2% and 11.85%, respectively, in 2008–09 reflecting non-availability of sufficient supply of electricity. Performance improvement of very small amount can lead to large contribution in financial terms, which can be utilized for capacity addition to reduce demand supply gap. Coal fired thermal power plants are main sources of electricity in India. In this paper, relative technical efficiency of 60 coal fired power plants has been evaluated and compared using CCR and BCC models of data envelopment analysis. Target benchmark of input variables has also been evaluated. Performance comparison includes small versus medium versus large power plants and also state owned versus central owned versus private owned. Result indicates poor performance of few power plants due to over use of input resources. Finding reveals that efficiency of small power plants is lower in comparison to medium and large category and also performance of state owned power plants is comparatively lower than central and privately owned. Study also suggests different measures to improve technical efficiency of the plants. - Highlights: ► This study evaluates relative technical efficiency of 60 coal fired thermal power plants of India. ► Input oriented CCR and BCC models of data envelopment analysis have been used. ► Small, medium and large power plants have been compared. ► Study will help investor while setting up new power projects. ► Power plants of different ownerships have also been compared.

  10. A Module For Thermal Pest Control In Stored Raw Materials Used In ...

    African Journals Online (AJOL)

    Pests are heterogeneous both in space and time, creating gradients and patterns depending on the prevailing environmental variables. Pest control efforts have utilized manipulations of these variables. This project is ona module for thermal control of pests using the hitherto waste steam from the indusries. The module is an ...

  11. Alpha Power Modulates Perception Independently of Endogenous Factors

    Directory of Open Access Journals (Sweden)

    Sasskia Brüers

    2018-04-01

    Full Text Available Oscillations are ubiquitous in the brain. Alpha oscillations in particular have been proposed to play an important role in sensory perception. Past studies have shown that the power of ongoing EEG oscillations in the alpha band is negatively correlated with visual outcome. Moreover, it also co-varies with other endogenous factors such as attention, vigilance, or alertness. In turn, these endogenous factors influence visual perception. Therefore, it remains unclear how much of the relation between alpha and perception is indirectly mediated by such endogenous factors, and how much reflects a direct causal influence of alpha rhythms on sensory neural processing. We propose to disentangle the direct from the indirect causal routes by introducing modulations of alpha power, independently of any fluctuations in endogenous factors. To this end, we use white-noise sequences to constrain the brain activity of 20 participants. The cross-correlation between the white-noise sequences and the concurrently recorded EEG reveals the impulse response function (IRF, a model of the systematic relationship between stimulation and brain response. These IRFs are then used to reconstruct rather than record the brain activity linked with new random sequences (by convolution. Interestingly, this reconstructed EEG only contains information about oscillations directly linked to the white-noise stimulation; fluctuations in attention and other endogenous factors may still modulate brain alpha rhythms during the task, but our reconstructed EEG is immune to these factors. We found that the detection of near-perceptual threshold targets embedded within these new white-noise sequences depended on the power of the ~10 Hz reconstructed EEG over parieto-occipital channels. Around the time of presentation, higher power led to poorer performance. Thus, fluctuations in alpha power, induced here by random luminance sequences, can directly influence perception: the relation between

  12. Thermal performance test for steam turbine of nuclear power plants

    International Nuclear Information System (INIS)

    Bu Yubing; Xu Zongfu; Wang Shiyong

    2014-01-01

    Through study of steam turbine thermal performance test of CPR1000 nuclear power plant, we solve the enthalpy calculation problems of the steam turbine in wet steam zone using heat balance method which can help to figure out the real overall heat balance diagram for the first time, and we develop a useful software for thermal heat balance calculation. Ling'ao phase II as an example, this paper includes test instrument layout, system isolation, risk control, data acquisition, wetness measurement, heat balance calculation, etc. (authors)

  13. Electrical power system integrated thermal/electrical system simulation

    International Nuclear Information System (INIS)

    Freeman, W.E.

    1992-01-01

    This paper adds thermal properties to previously developed electrical Saber templates and incorporates these templates into a functional Electrical Power Subsystem (EPS) simulation. These combined electrical and thermal templates enable the complete and realistic simulation of a vehicle EPS on-orbit. Applications include on-orbit energy balance determinations for system load changes, initial array and battery EPS sizing for new EPS development, and array and battery technology trade studies. This effort proves the versatility of the Saber simulation program in handling varied and complex simulations accurately and in a reasonable amount of computer time. 9 refs

  14. Research on Power System Scheduling Improving Wind Power Accommodation Considering Thermal Energy Storage and Flexible Load

    Science.gov (United States)

    Zou, Chenlu; Cui, Xue; Wang, Heng; Zhou, Bin; Liu, Yang

    2018-01-01

    In the case of rapid development of wind power and heavy wind curtailment, the study of wind power accommodation of combined heat and power system has become the focus of attention. A two-stage scheduling model contains of wind power, thermal energy storage, CHP unit and flexible load were constructed. This model with the objective function of minimizing wind curtailment and the operation cost of units while taking into account of the total coal consumption of units, constraint of thermal energy storage and electricity-heat characteristic of CHP. This paper uses MICA to solve the problem of too many constraints and make the solution more feasible. A numerical example showed that the two stage decision scheduling model can consume more wind power, and it could provide a reference for combined heat and power system short-term operation

  15. A Thermal Runaway Simulation on a Lithium Titanate Battery and the Battery Module

    Directory of Open Access Journals (Sweden)

    Man Chen

    2015-01-01

    Full Text Available Based on the electrochemical and thermal model, a coupled electro-thermal runaway model was developed and implemented using finite element methods. The thermal decomposition reactions when the battery temperature exceeds the material decomposition temperature were embedded into the model. The temperature variations of a lithium titanate battery during a series of charge-discharge cycles under different current rates were simulated. The results of temperature and heat generation rate demonstrate that the greater the current, the faster the battery temperature is rising. Furthermore, the thermal influence of the overheated cell on surrounding batteries in the module was simulated, and the variation of temperature and heat generation during thermal runaway was obtained. It was found that the overheated cell can induce thermal runaway in other adjacent cells within 3 mm distance in the battery module if the accumulated heat is not dissipated rapidly.

  16. A new high power thermal battery cathode material

    International Nuclear Information System (INIS)

    Faul, I.

    1986-01-01

    Smaller and lighter thermal batteries are major aims of the battery research programme at RAE Farnborough. Modern designs of thermal batteries, for use as power supplies in weapon systems, almost invariably use the Li:molten salt:FeS/sub 2/ system because of the significant increase in energy density achieved in comparison with the earlier Ca/CaCrO/sub 4/ couple. The disadvantage of the FeS/sub 2/ system is that the working cell voltage, between 1.5 and 2.0 V, is significantly lower so leading to more cells per battery than the earlier system. Further work at RAE and MSA (Britain) Ltd showed that the poor thermal stability of TiS/sub 2/ limited its use in thermal batteries, whilst the more stable V/sub 6/O/sub 13/ oxidised the electrolyte, giving poor efficiencies. However, the resulting reduced vanadium oxide material, subsequently called lithiated vanadium oxide (LVO), was found to be an excellent high voltage thermal battery cathode, being the subject of both UK and US patents. In this study both V/sub 6/O/sub 13/ made by the direct stoichiometric reaction of V/sub 2/O/sub 5/ and V and also by thermal decomposition of NH/sub 4/VO/sub 3/ under argon, have been used with equal success as the starting material for the preparation of LVO

  17. Thermal Loading and Lifetime Estimation for Power Device Considering Mission Profiles in Wind Power Converter

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2015-01-01

    for the reliability improvement and also for cost reduction of wind power technology. Unfortunately, the existing lifetime estimation methods for the power electronic converter are not yet suitable in the wind power application, because the comprehensive mission profiles are not well specified and included......As a key component in the wind turbine system, the power electronic converter and its power semiconductors suffer from complicated power loadings related to environment, and are proven to have high failure rates. Therefore, correct lifetime estimation of wind power converter is crucial...... devices, more detailed information of the lifetime-related performance in wind power converter can be obtained. Some experimental results are also included to validate the thermal behavior of power device under different mission profiles....

  18. Thermal effluents from nuclear power plant influences species distribution and thermal tolerance of fishes in reservoirs

    International Nuclear Information System (INIS)

    Pal, A.K.; Das, T.; Dalvi, R.S.; Bagchi, S.; Manush, S.M.; Ayyappan, S.; Chandrachoodan, P.P.; Apte, S.K.; Ravi, P.M.

    2007-01-01

    During electricity generation water bodies like reservoir act as a heat sink for thermal effluent discharges from nuclear power plant. We hypothesized that the fish fauna gets distributed according to their temperature preference in the thermal gradient. In a simulated environment using critical thermal methodology (CTM), we assessed thermal tolerance and metabolic profile of fishes (Puntius filamentosus, Parluciosoma daniconius, Ompok malabaricus, Mastacembelus armatus, Labeo calbasu, Horabragrus brachysoma, Etroplus suratensis, Danio aequipinnatus and Gonoproktopterus curmuca) collected from Kadra reservoir in Karnataka state. Results of CTM tests agrees with the species abundance as per the temperature gradient formed in the reservoir due to thermal effluent discharge. E. suratensis and H. brachysoma) appear to be adapted to high temperature (with high CTMax and CTMin values) and are in abundance at point of thermal discharge. Similarly, P. daniconius, appear to be adapted to cold (low CTM values) is in abundance in lower stretches of Kadra reservoir. Overall results indicate that discharge form nuclear power plant influences the species biodiversity in enclosed water bodies. (author)

  19. Thermal analysis of a conceptual design for a 250 W(e) GPHS/FPSE space power system

    International Nuclear Information System (INIS)

    Mccomas, T.J.; Dugan, E.T.

    1991-01-01

    A thermal analysis has been performed for a 250-W(e) space nuclear power system which combines the US Department of Energy's general purpose heat source (GPHS) modules with a state-of-the-art free-piston Stirling engine (FPSE). The focus of the analysis is on the temperature of the indium fuel clad within the GPHS modules. The thermal analysis results indicate fuel clad temperatures slightly higher than the design goal temperature of 1573 K. The results are considered favorable due to numerous conservative assumptions used. To demonstrate the effects of the conservatism, a brief sensitivity analysis is performed in which a few of the key system parameters are varied to determine their effect on the fuel clad temperatures. It is shown that thermal analysis of a more detailed thermal mode should yield fuel clad temperatures below 1573 K. 3 refs

  20. Simulation of thermal properties of the silicon detector modules in ATLAS

    CERN Document Server

    Duerdoth, I P; Yuldashev, B S

    2002-01-01

    The temperature distribution and power flow from cell on the Silicon Module of the Forward Semiconductor Tracker in the ATLAS experiment have been simulated for irradiated detector. Power generated by conduction was compared for the modules with one and two cooling points. To obtain an optimal cooling temperature, the temperature of the hottest cell was plotted against power on the silicon module. The analysis of the approximation function and values for the critical power for each cooling temperature are presented. The optimal value of the cooling temperature occurred to be 260 K. (author)

  1. Fifth parabolic dish solar thermal power program annual review: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    None

    1984-03-01

    The primary objective of the Review was to present the results of activities within the Parabolic Dish Technology and Module/Systems Development element of the Department of Energy's Solar Thermal Energy Systems Program. The Review consisted of nine technical sessions covering overall Project and Program aspects, Stirling and Brayton module development, concentrator and engine/receiver development, and associated hardware and test results to date; distributed systems operating experience; international dish development activities; and non-DOE-sponsored domestic dish activities. A panel discussion concerning business views of solar electric generation was held. These Proceedings contain the texts of presentations made at the Review, as submitted by their authors at the beginning of the Review; therefore, they may vary slightly from the actual presentations in the technical sessions.

  2. Mechanical and Thermal Characterisation of a TT Half-Module Prototype

    CERN Document Server

    Lehner, F; Pangilinan, M; Siegler, M

    2005-01-01

    This note describes the mechanical effects of thermal cycles on a TT half-module, to demonstrate that the detectors can withstand the expected thermal gradients without damage. The stress transferred by the carbon fiber rails and the ceramic to the silicon sensors was investigated, and the deformation that occurred during these tests was measured by strain gauges that were attached to sensors on a test half-module. In addition, heat transfer through the carbon fiber rails was studied. Furthermore, we present a comparison of different materials proposed to build the carbon fiber rails of the modules.

  3. Application of advanced thermal management technologies to the ATLAS SCT barrel module baseboards

    Energy Technology Data Exchange (ETDEWEB)

    Apsimon, R.J. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom); Batchelor, L.E. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom); Beck, G.A. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Canard, P. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Carter, A.A. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)]. E-mail: a.a.carter@qmul.ac.uk; Carter, J.R. [Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Davis, V.R. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom); Oliveira, R. de [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Gibson, M.D. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom); Hominal, L. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Ilie, D.M. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Ilie, S.D. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Leboube, C.G. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Mistry, J. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Morin, J. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Morris, J.; Nagai, K. [Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Sexton, I.; Thery, X. [European Laboratory for Particle Physics (CERN), 1211 Geneva 23 (Switzerland); Tyndel, M. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 OQX (United Kingdom)

    2006-09-15

    The paper describes the application of advanced thermal management technologies to the design and production of the barrel module baseboard of the SemiConductor Tracker (SCT) of the ATLAS experiment at the Large Hadron Collider (LHC). The barrel modules contain silicon microstrip sensors and readout ASICs for tracking charged particles, and the baseboard forms the central element of the module, providing both its necessary thermal management and its mechanical structure. The baseboard requirements and specifications are given, and design and fabrication details are described. The properties of the 3000 baseboards successfully produced for the SCT are summarised.

  4. Mission-profile-based stress analysis of bond-wires in SiC power modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Iannuzzo, Francesco; Blaabjerg, Frede

    2016-01-01

    This paper proposes a novel mission-profile-based reliability analysis approach for stress on bond wires in Silicon Carbide (SiC) MOSFET power modules using statistics and thermo-mechanical FEM analysis. In the proposed approach, both the operational and environmental thermal stresses are taken...... into account. The approach uses a two-dimension statistical analysis of the operating conditions in a real one-year mission profile sampled at time frames 5 minutes long. For every statistical bin corresponding to a given operating condition, the junction temperature evolution is estimated by a thermal network...... and the mechanical stress on bond wires is consequently extracted by finite-element simulations. In the final step, the considered mission profile is translated in a stress sequence to be used for Rainflow counting calculation and lifetime estimation....

  5. Effective Thermal Analysis of Using Peltier Module for Desalination Process

    OpenAIRE

    Hayder Al-Madhhachi

    2018-01-01

    The key objective of this study is to analyse the heat transfer processes involved in the evaporation and condensation of water in a water distillation system employing a thermoelectric module. This analysis can help to increase the water production and to enhance the system performance. For the analysis, a water distillation unit prototype integrated with a thermoelectric module was designed and fabricated. A theoretical model is developed to study the effect of the heat added, transferred a...

  6. Thermal and Performance Analysis of a Photovoltaic Module with an Integrated Energy Storage System

    Directory of Open Access Journals (Sweden)

    Manel Hammami

    2017-10-01

    Full Text Available This paper is proposing and analyzing an electric energy storage system fully integrated with a photovoltaic PV module, composed by a set of lithium-iron-phosphate (LiFePO4 flat batteries, which constitutes a generation-storage PV unit. The batteries were surface-mounted on the back side of the PV module, distant from the PV backsheet, without exceeding the PV frame size. An additional low-emissivity sheet was introduced to shield the batteries from the backsheet thermal irradiance. The challenge addressed in this paper is to evaluate the PV cell temperature increase, due to the reduced thermal exchanges on the back of the module, and to estimate the temperature of the batteries, verifying their thermal constraints. Two one-dimensional (1D thermal models, numerically implemented by using the thermal library of Simulink-Matlab accounting for all the heat exchanges, are here proposed: one related to the original PV module, the other related to the portion of the area of the PV module in correspondence of the proposed energy-storage system. Convective and radiative coefficients were then calculated in relation to different configurations and ambient conditions. The model validation has been carried out considering the PV module to be at the nominal operating cell temperature (NOCT, and by specific experimental measurements with a thermographic camera. Finally, appropriate models were used to evaluate the increasing cell batteries temperature in different environmental conditions.

  7. Effective Thermal Analysis of Using Peltier Module for Desalination Process

    Directory of Open Access Journals (Sweden)

    Hayder Al-Madhhachi

    2018-01-01

    Full Text Available The key objective of this study is to analyse the heat transfer processes involved in the evaporation and condensation of water in a water distillation system employing a thermoelectric module. This analysis can help to increase the water production and to enhance the system performance. For the analysis, a water distillation unit prototype integrated with a thermoelectric module was designed and fabricated. A theoretical model is developed to study the effect of the heat added, transferred and removed, in forced convection and laminar flow, during the evaporation and condensation processes. The thermoelectric module is used to convert electricity into heat under Peltier effect and control precisely the absorbed and released heat at the cold and hot sides of the module, respectively. Temperatures of water, vapour, condenser, cold and hot sides of the thermoelectric module and water production have been measured experimentally under steady state operation. The theoretical and experimental water production were found to be in agreement. The amount of heat that needs to be evaporated from water-vapour interface and transferred through the condenser surface to the thermoelectric module is crucial for the design and optimization of distillation systems.

  8. Control of thermal therapies with moving power deposition field

    International Nuclear Information System (INIS)

    Arora, Dhiraj; Minor, Mark A; Skliar, Mikhail; Roemer, Robert B

    2006-01-01

    A thermal therapy feedback control approach to control thermal dose using a moving power deposition field is developed and evaluated using simulations. A normal tissue safety objective is incorporated in the controller design by imposing constraints on temperature elevations at selected normal tissue locations. The proposed control technique consists of two stages. The first stage uses a model-based sliding mode controller that dynamically generates an 'ideal' power deposition profile which is generally unrealizable with available heating modalities. Subsequently, in order to approximately realize this spatially distributed idealized power deposition, a constrained quadratic optimizer is implemented to compute intensities and dwell times for a set of pre-selected power deposition fields created by a scanned focused transducer. The dwell times for various power deposition profiles are dynamically generated online as opposed to the commonly employed a priori-decided heating strategies. Dynamic intensity and trajectory generation safeguards the treatment outcome against modelling uncertainties and unknown disturbances. The controller is designed to enforce simultaneous activation of multiple normal tissue temperature constraints by rapidly switching between various power deposition profiles. The hypothesis behind the controller design is that the simultaneous activation of multiple constraints substantially reduces treatment time without compromising normal tissue safety. The controller performance and robustness with respect to parameter uncertainties is evaluated using simulations. The results demonstrate that the proposed controller can successfully deliver the desired thermal dose to the target while maintaining the temperatures at the user-specified normal tissue locations at or below the maximum allowable values. Although demonstrated for the case of a scanned focused ultrasound transducer, the developed approach can be extended to other heating modalities with

  9. Development of a 30-cm ion thruster thermal-vacuum power processor

    Science.gov (United States)

    Herron, B. G.

    1976-01-01

    The 30-cm Hg electron-bombardment ion thruster presently under development has reached engineering model status and is generally accepted as the prime propulsion thruster module to be used on the earliest solar electric propulsion missions. This paper presents the results of a related program to develop a transistorized 3-kW Thermal-Vacuum Breadboard (TVBB) Power Processor for this thruster. Emphasized in the paper are the implemented electrical and mechanical designs as well as the resultant system performance achieved over a range of test conditions. In addition, design modifications affording improved performance are identified and discussed.

  10. Temperature Effect on Power Drop of Different Photovoltaic Modules

    Directory of Open Access Journals (Sweden)

    Emad Talib Hahsim

    2016-05-01

    Full Text Available Solar module operating temperature is the second major factor affects the performance of solar photovoltaic panels after the amount of solar radiation. This paper presents a performance comparison of mono-crystalline Silicon (mc-Si, poly-crystalline Silicon (pc-Si, amorphous Silicon (a-Si and Cupper Indium Gallium di-selenide (CIGS photovoltaic technologies under Climate Conditions of Baghdad city. Temperature influence on the solar modules electric output parameters was investigated experimentally and their temperature coefficients was calculated. These temperature coefficients are important for all systems design and sizing. The experimental results revealed that the pc-Si module showed a decrease in open circuit voltage by -0.0912V/ºC while mc-Si and a-Si had nearly -0.07V/ºC and the CIGS has -0.0123V/ºC. The results showed a slightly increase in short circuit current with temperature increasing about 0.3mA/ºC ,4.4mA/ºC and 0.9mA/ºC for mc-Si , pc-Si and both a-Si and CIGS. The mc-Si had the largest drop in output power about -0.1353W/ºC while -0.0915, -0.0114 and -0.0276 W/ºC for pc-Si, a-Si and CIGS respectively. The amorphous silicon is the more suitable module for high operation temperature but it has the lowest conversion efficiency between the tested modules.

  11. Impact of modulation strategies on power devices loading for 10 MW multilevel wind power converter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Isidori, Andrea; Rossi, Fabio Mario

    2012-01-01

    This paper focuses on the control and modulation of a three-level Neutral Point Clamped (3L-NPC) back-to-back full scale converter for a 10 MW direct-drive wind turbine, equipped with a Permanent Magnet Synchronous Generator (PMSG). Emphasis is oriented towards the investigation of the power losses...

  12. Hydro-thermal power flow scheduling accounting for head variations

    International Nuclear Information System (INIS)

    El-Hawary, M.E.; Ravindranath, K.M.

    1992-01-01

    In this paper the authors treat the problem of optimal economic operation of hydrothermal electric power systems with variable head hydro plants employing the power flow equations to represent the network. Newton's method is used to solve the problem for a number of test systems. A comparison with solutions with fixed head is presented. In general the optimal schedule requires higher slack bus and thermal power generation and cost in the case of variable head hydro plant than that required by the fixed head hydro plant in all demand periods. Correspondingly, the hydro generation is less in the case of variable head hydro plant compared to fixed head hydro plant. A negligible difference in voltage magnitudes in all the time intervals, but it is observed that slightly higher voltages occur in the case of the fixed head hydro plant. Higher power and energy losses occur in the case of variable head hydro plants compared to the fixed head hydro plants

  13. Thermal conductivity engineering in width-modulated silicon nanowires and thermoelectric efficiency enhancement

    Science.gov (United States)

    Zianni, Xanthippi

    2018-03-01

    Width-modulated nanowires have been proposed as efficient thermoelectric materials. Here, the electron and phonon transport properties and the thermoelectric efficiency are discussed for dimensions above the quantum confinement regime. The thermal conductivity decreases dramatically in the presence of thin constrictions due to their ballistic thermal resistance. It shows a scaling behavior upon the width-modulation rate that allows for thermal conductivity engineering. The electron conductivity also decreases due to enhanced boundary scattering by the constrictions. The effect of boundary scattering is weaker for electrons than for phonons and the overall thermoelectric efficiency is enhanced. A ZT enhancement by a factor of 20-30 is predicted for width-modulated nanowires compared to bulk silicon. Our findings indicate that width-modulated nanostructures are promising for developing silicon nanostructures with high thermoelectric efficiency.

  14. LDMOS Channel Thermometer Based on a Thermal Resistance Sensor for Balancing Temperature in Monolithic Power ICs

    Directory of Open Access Journals (Sweden)

    Tingyou Lin

    2017-06-01

    Full Text Available This paper presents a method of thermal balancing for monolithic power integrated circuits (ICs. An on-chip temperature monitoring sensor that consists of a poly resistor strip in each of multiple parallel MOSFET banks is developed. A temperature-to-frequency converter (TFC is proposed to quantize on-chip temperature. A pulse-width-modulation (PWM methodology is developed to balance the channel temperature based on the quantization. The modulated PWM pulses control the hottest of metal-oxide-semiconductor field-effect transistor (MOSFET bank to reduce its power dissipation and heat generation. A test chip with eight parallel MOSFET banks is fabricated in TSMC 0.25 μm HV BCD processes, and total area is 900 × 914 μm2. The maximal temperature variation among the eight banks can reduce to 2.8 °C by the proposed thermal balancing system from 9.5 °C with 1.5 W dissipation. As a result, our proposed system improves the lifetime of a power MOSFET by 20%.

  15. Low-Cost Radiator for Fission Power Thermal Control

    Science.gov (United States)

    Maxwell, Taylor; Tarau, Calin; Anderson, William; Hartenstine, John; Stern, Theodore; Walmsley, Nicholas; Briggs, Maxwell

    2014-01-01

    NASA Glenn Research Center (GRC) is developing fission power system technology for future Lunar surface power applications. The systems are envisioned in the 10 to 100kW(sub e) range and have an anticipated design life of 8 to 15 years with no maintenance. NASA GRC is currently setting up a 55 kW(sub e) non-nuclear system ground test in thermal-vacuum to validate technologies required to transfer reactor heat, convert the heat into electricity, reject waste heat, process the electrical output, and demonstrate overall system performance. Reducing the radiator mass, size, and cost is essential to the success of the program. To meet these goals, Advanced Cooling Technologies, Inc. (ACT) and Vanguard Space Technologies, Inc. (VST) are developing a single facesheet radiator with heat pipes directly bonded to the facesheet. The facesheet material is a graphite fiber reinforced composite (GFRC) and the heat pipes are titanium/water. By directly bonding a single facesheet to the heat pipes, several heavy and expensive components can be eliminated from the traditional radiator design such as, POC(TradeMark) foam saddles, aluminum honeycomb, and a second facesheet. A two-heat pipe radiator prototype, based on the single facesheet direct-bond concept, was fabricated and tested to verify the ability of the direct-bond joint to withstand coefficient of thermal expansion (CTE) induced stresses during thermal cycling. The thermal gradients along the bonds were measured before and after thermal cycle tests to determine if the performance degraded. Overall, the results indicated that the initial uniformity of the adhesive was poor along one of the heat pipes. However, both direct bond joints showed no measureable amount of degradation after being thermally cycled at both moderate and aggressive conditions.

  16. Scaling behavior of the thermal conductivity of width-modulated nanowires and nanofilms for heat transfer control at the nanoscale.

    Science.gov (United States)

    Zianni, Xanthippi; Jean, Valentin; Termentzidis, Konstantinos; Lacroix, David

    2014-11-21

    We report on scaling behavior of the thermal conductivity of width-modulated nanowires and nanofilms that have been studied with the phonon Monte Carlo technique. It has been found that the reduction of the thermal conductivity scales with the nanostructure transmissivity, a property entirely determined by the modulation geometry, irrespectively of the material choice. Tuning of the thermal conductivity is possible by the nanostructure width-modulation without strict limitations for the modulation profile. In addition, a very significant constriction thermal resistance due to width-discontinuity has been identified, in analogy to the contact thermal resistance between two dissimilar materials. The constriction thermal resistance also scales with the modulated nanostructure transmissivity. Our conclusions are generic indicating that a wide range of materials can be used for the modulated nanostructures. Direct heat flow control can be provided by designing the nanostructure width-modulation.

  17. Transient electro-thermal modeling of bipolar power semiconductor devices

    CERN Document Server

    Gachovska, Tanya Kirilova; Du, Bin

    2013-01-01

    This book presents physics-based electro-thermal models of bipolar power semiconductor devices including their packages, and describes their implementation in MATLAB and Simulink. It is a continuation of our first book Modeling of Bipolar Power Semiconductor Devices. The device electrical models are developed by subdividing the devices into different regions and the operations in each region, along with the interactions at the interfaces, are analyzed using the basic semiconductor physics equations that govern device behavior. The Fourier series solution is used to solve the ambipolar diffusio

  18. State and development of the technology of thermal power plants

    International Nuclear Information System (INIS)

    Peter, F.; Schueller, K.H.

    1981-01-01

    Like in the past thermal power plants shall have to be designed also in the future in a way that a sufficient, low-priced and environment-preserving electricity and heat supply can be granted. The technology applied today in fossil-fuel and nuclear power plants and its further development is outlined under the aspects of a better utilization of primary energy, the substitution of petroleum and, in the long term, also of natural gas and coal, and of the extended protection of the environment against harmful influences. (orig.) [de

  19. Pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2008-01-01

    This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

  20. Gyrocon: a deflection-modulated, high-power microwave amplifier

    International Nuclear Information System (INIS)

    Tallerico, P.J.

    1977-10-01

    A large-signal, relativistic theory of the electron-field interaction in a new class of microwave amplifiers is presented and applied to the analysis of a high-power, 450-MHz amplifier for accelerator applications. The analysis indicates that electronic efficiencies in excess of 90 percent are obtainable and that overall efficiencies of 90 percent are possible. The amplifier is unique in several respects; the electron velocity is perpendicular to the circuit energy flow, the device uses a fast-wave circuit, and the electron beam is deflection modulated

  1. Feasibility study on Bobovdol thermal power plant upgrading project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    A survey has been made in relation with the improvement project intended of energy conservation, and reduction of global warming gas emission at the Bobovdol thermal power plant located in the suburb of Sofia, the capital of the Republic of Bulgaria. The existing Bobovdol power plant having a total capacity of 630 MW with three generators is a coal burning thermal power plant having been used already for 23 to 27 years, hence over-aged. The survey has discussed an improvement project of scrap-and-build type to make the plant a high-efficiency gas combined cycle power plant using gas turbines. The project calls for building 210-MW gas combined power generation facilities having 70-MW gas turbines, one each in three stages in 2007, 2012 and 2017. As a result of the discussions, the fuel consumption reducing rate was found to reach 37.99%, whereas the cumulative energy saving quantity in 41 years will reach 16.37 million tons of fuel oil equivalent. In addition, the reduction rate of global warming gas emission is 57.75%, and the cumulative reduction quantity in 41 years is 105.18 million tons. (NEDO)

  2. Environmental impact assessment of coal fired thermal power stations

    International Nuclear Information System (INIS)

    Nambi, K.S.V.; Sadasivan, S.; Negi, B.S.; Meenakshy, V.

    1992-01-01

    Coal fly ash samples collected from various thermal power plants and one lignite ash sample were analysed for various elements such as As, Ca, Ce, Co, Cr, Cu, Eu, Fe, Hf, K, La, Lu, Mn, Na, Ni, Pb, Rb, Se, Si, Sb, Sc, Sm, Sr, Ti, V, Yb and Zn using energy dispersive X-ray fluorescence and instrumental neutron activation analysis methods. The two-step maximum leachability test was also performed on all fly ash samples. 13 refs, 9 tabs

  3. Major enhancement of extra-low-frequency radiation by increasing the high-frequency heating wave power in electrojet modulation

    International Nuclear Information System (INIS)

    Kuo, S.P.; Lee, S.H.; Kossey, Paul

    2002-01-01

    Extra-low-frequency (ELF) wave generation by modulated polar electrojet currents is studied. The amplitude-modulated high-frequency (HF) heating wave excites a stimulated thermal instability to enhance the electrojet current modulation by the passive Ohmic heating process. Inelastic collisions of electrons with neutral particles (mainly due to vibrational excitation of N 2 ) damp nonlinearly this instability, which is normally saturated at low levels. However, the electron's inelastic collision loss rate drops rapidly to a low value in the energy regime from 3.5 to 6 eV. As the power of the modulated HF heating wave exceeds a threshold level, it is shown that significant electron heating enhanced by the stimulated thermal instability can indeed cause a steep drop in the electron inelastic collision loss rate. Consequently, this instability saturates at a much higher level, resulting to a near step increase (of about 10-13 dB, depending on the modulation wave form) in the spectral intensity of ELF radiation. The dependence of the threshold power of the HF heating wave on the modulation frequency is determined

  4. Solar thermal electric power generation - an attractive option for Pakistan

    International Nuclear Information System (INIS)

    Khan, N.A

    1999-01-01

    Solar Thermal Energy is being successfully used for production of electricity in few developed countries for more than 10 years. In solar Electric Generating Systems high temperature is generated by concentrating solar energy on black absorber pipe in evacuated glass tubes. This heat is absorbed and transported with the help of high temperature oil in to highly insulated heat exchanger storage tanks. They are subsequently used to produce steam that generates power through steam turbines as in standard thermal power plants. Various components involved in Solar thermal field have been developed at the Solar Systems Laboratory of College of EME, NUST Rawalpindi. It is considered as a cost effective alternate for power generation. The research has been partially sponsored by Ministry of Science and Technology under its Public Sector Development Program (PSDP) in (1996-1998). Parabolic mirror design, fabrication, polishing, installation, solar tracking, absorber pipe, glass tubes, steam generation al have been developed. This paper will cover the details of indigenous technological break through made in this direction. (author)

  5. Portable low-power thermal cycler with dual thin-film Pt heaters for a polymeric PCR chip.

    Science.gov (United States)

    Jeong, Sangdo; Lim, Juhun; Kim, Mi-Young; Yeom, JiHye; Cho, Hyunmin; Lee, Hyunjung; Shin, Yong-Beom; Lee, Jong-Hyun

    2018-01-29

    Polymerase chain reaction (PCR) has been widely used for major definite diagnostic tool, but very limited its place used only indoor such as hospital or diagnosis lab. For the rapid on-site detection of pathogen in an outdoor environment, a low-power cordless polymerase chain reaction (PCR) thermal cycler is crucial module. At this point of view, we proposed a low-power PCR thermal cycler that could be operated in an outdoor anywhere. The disposable PCR chip was made of a polymeric (PI/PET) film to reduce the thermal mass. A dual arrangement of the Pt heaters, which were positioned on the top and bottom of the PCR chip, improved the temperature uniformity. The temperature sensor, which was made of the same material as the heater, utilized the temperature dependence of the Pt resistor to ensure simple fabrication of the temperature sensor. Cooling the PCR chip using dual blower fans enabled thermal cycling to operate with a lower power than that of a Peltier element with a high power consumption. The PCR components were electrically connected to a control module that could be operated with a Li-ion battery (12 V), and the PCR conditions (temperature, time, cycle, etc.) were inputted on a touch screen. For 30 PCR cycles, the accumulated power consumption of heating and cooling was 7.3 Wh, which is easily available from a compact battery. Escherichia coli genomic DNA (510 bp) was amplified using the proposed PCR thermal cycler and the disposable PCR chip. A similar DNA amplification capability was confirmed using the proposed portable and low-power thermal cycler compared with a conventional thermal cycler.

  6. Failure at Zainsk thermal power station: lesson for thermal and nuclear power stations

    International Nuclear Information System (INIS)

    Derkach, A.L.; Klyuchnikov, A.A.; Fedorenko, G.M.; Kuz'min, V.V.

    2007-01-01

    An account of system failure at Zainsk Thermal PS on January 1-st, 1979 is given. The cause of failure - sudden unauthorized energizing of block transformer which led to a direct asynchronous start of 200 MW turbine generator from grid. The failure resulted in the explosion and fire in generator, shaft destruction, and the damage of the machine hall's roof. The core roots of the failure have been scrutinised

  7. Amelioration of Electrical Power Quality based on Modulated Power Filter Compensator

    Directory of Open Access Journals (Sweden)

    Karrar Hameed Kadhim

    2017-08-01

    Full Text Available This paper deals with the performance of modeling and implementation of Modulated Power Filter Compensator ( MPFC based on synchronous generator to enhance Electrical Power Quality (EPQ performance , rectification power factor , voltage fixity and decreasing transmission line losses for 300 km transmission line . In this paper (MPFC sketch attendants for intelligent network stability and optimum exploitation. The proposal Flexible AC Transmission Systems ( FACTS can be expanded to distributed renewable energy interface and exploitation systems and also will be easy to modify for voltage fixity, Achieve the required stability, perfect usage and Compensation requirements. MATLAB SIMLINK version R2009b were used as a model of (MPFC.

  8. X-Parameter Based Modelling of Polar Modulated Power Amplifiers

    DEFF Research Database (Denmark)

    Wang, Yelin; Nielsen, Troels Studsgaard; Sira, Daniel

    2013-01-01

    X-parameters are developed as an extension of S-parameters capable of modelling non-linear devices driven by large signals. They are suitable for devices having only radio frequency (RF) and DC ports. In a polar power amplifier (PA), phase and envelope of the input modulated signal are applied...... at separate ports and the envelope port is neither an RF nor a DC port. As a result, X-parameters may fail to characterise the effect of the envelope port excitation and consequently the polar PA. This study introduces a solution to the problem for a commercial polar PA. In this solution, the RF-phase path...... PA for simulations. The simulated error vector magnitude (EVM) and adjacent channel power ratio (ACPR) were compared with the measured data to validate the model. The maximum differences between the simulated and measured EVM and ACPR are less than 2% point and 3 dB, respectively....

  9. A review on lithium-ion power battery thermal management technologies and thermal safety

    Science.gov (United States)

    An, Zhoujian; Jia, Li; Ding, Yong; Dang, Chao; Li, Xuejiao

    2017-10-01

    Lithium-ion power battery has become one of the main power sources for electric vehicles and hybrid electric vehicles because of superior performance compared with other power sources. In order to ensure the safety and improve the performance, the maximum operating temperature and local temperature difference of batteries must be maintained in an appropriate range. The effect of temperature on the capacity fade and aging are simply investigated. The electrode structure, including electrode thickness, particle size and porosity, are analyzed. It is found that all of them have significant influences on the heat generation of battery. Details of various thermal management technologies, namely air based, phase change material based, heat pipe based and liquid based, are discussed and compared from the perspective of improving the external heat dissipation. The selection of different battery thermal management (BTM) technologies should be based on the cooling demand and applications, and liquid cooling is suggested being the most suitable method for large-scale battery pack charged/discharged at higher C-rate and in high-temperature environment. The thermal safety in the respect of propagation and suppression of thermal runaway is analyzed.

  10. Numerical Modeling of Water Thermal Plumes Emitted by Thermal Power Plants

    Directory of Open Access Journals (Sweden)

    Azucena Durán-Colmenares

    2016-10-01

    Full Text Available This work focuses on the study of thermal dispersion of plumes emitted by power plants into the sea. Wastewater discharge from power stations causes impacts that require investigation or monitoring. A study to characterize the physical effects of thermal plumes into the sea is carried out here by numerical modeling and field measurements. The case study is the thermal discharges of the Presidente Adolfo López Mateos Power Plant, located in Veracruz, on the coast of the Gulf of Mexico. This plant is managed by the Federal Electricity Commission of Mexico. The physical effects of such plumes are related to the increase of seawater temperature caused by the hot water discharge of the plant. We focus on the implementation, calibration, and validation of the Delft3D-FLOW model, which solves the shallow-water equations. The numerical simulations consider a critical scenario where meteorological and oceanographic parameters are taken into account to reproduce the proper physical conditions of the environment. The results show a local physical effect of the thermal plumes within the study zone, given the predominant strong winds conditions of the scenario under study.

  11. Advanced Accelerated Power Cycling Test for Reliability Investigation of Power Device Modules

    DEFF Research Database (Denmark)

    Choi, Uimin; Jørgensen, Søren; Blaabjerg, Frede

    2016-01-01

    This paper presents an apparatus and methodology for an advanced accelerated power cycling test of insulated-gate bipolar transistor (IGBT) modules. In this test, the accelerated power cycling test can be performed under more realistic electrical operating conditions with online wear-out monitoring...... of tested power IGBT module. The various realistic electrical operating conditions close to real three-phase converter applications can be achieved by the simple control method. Further, by the proposed concept of applying the temperature stress, it is possible to apply various magnitudes of temperature...... swing in a short cycle period and to change the temperature cycle period easily. Thanks to a short temperature cycle period, test results can be obtained in a reasonable test time. A detailed explanation of apparatus such as configuration and control methods for the different functions of accelerated...

  12. Development of whole core thermal-hydraulic analysis program ACT. 3. Coupling core module with primary heat transport system module

    International Nuclear Information System (INIS)

    Ohtaka, Masahiko; Ohshima, Hiroyuki

    1998-10-01

    A whole core thermal-hydraulic analysis program ACT is being developed for the purpose of evaluating detailed in-core thermal hydraulic phenomena of fast reactors including inter-wrapper flow under various reactor operation conditions. In this work, the core module as a main part of the ACT developed last year, which simulates thermal-hydraulics in the subassemblies and the inter-subassembly gaps, was coupled with an one dimensional plant system thermal-hydraulic analysis code LEDHER to simulate transients in the primary heat transport system and to give appropriate boundary conditions to the core model. The effective algorithm to couple these two calculation modules was developed, which required minimum modification of them. In order to couple these two calculation modules on the computing system, parallel computing technique using PVM (Parallel Virtual Machine) programming environment was applied. The code system was applied to analyze an out-of-pile sodium experiment simulating core with 7 subassemblies under transient condition for code verification. It was confirmed that the analytical results show a similar tendency of experimental results. (author)

  13. Energy audit: thermal power, combined cycle, and cogeneration plants

    Energy Technology Data Exchange (ETDEWEB)

    Abbi, Yash Pal

    2012-07-01

    The availability of fossil fuels required for power plants is reducing and their costs increasing rapidly. This gives rise to increase in the cost of generation of electricity. But electricity regulators have to control the price of electricity so that consumers are not stressed with high costs. In addition, environmental considerations are forcing power plants to reduce CO2 emissions. Under these circumstances, power plants are constantly under pressure to improve the efficiency of operating plants, and to reduce fuel consumption. In order to progress in this direction, it is important that power plants regularly audit their energy use in terms of the operating plant heat rate and auxiliary power consumption. The author attempts to refresh the fundamentals of the science and engineering of thermal power plants, establish its link with the real power plant performance data through case studies, and further develop techno-economics of the energy efficiency improvement measures. This book will rekindle interest in energy audits and analysis of the data for designing and implementation of energy conservation measures on a continuous basis.

  14. A performance analysis of solar chimney thermal power systems

    Directory of Open Access Journals (Sweden)

    Al-Dabbas Awwad Mohammed

    2011-01-01

    Full Text Available The objective of this study was to evaluate the solar chimney performance theoretically (techno-economic. A mathematical model was developed to estimate the following parameter: Power output, Pressure drop across the turbine, the max chimney height, Airflow temperature, and the overall efficiency of solar chimney. The mathematical model was validated with experimental data from the prototype in Manzanares power. It can be concluded that the differential pressure of collector-chimney transition section in the system, is increase with the increase of solar radiation intensity. The specific system costs are between 2000 Eur/kW and 5000 Eur/kW depending on the system size, system concept and storage size. Hence, a 50 MWe solar thermal power plant will cost 100-250 Eur million. At very good sites, today’s solar thermal power plants can generate electricity in the range of 0.15 Eur/kWh, and series production could soon bring down these costs below 0.10 Eur /kWh.

  15. Alternative trends in development of thermal power plants

    International Nuclear Information System (INIS)

    Prisyazhniuk, Vitaly A.

    2008-01-01

    Thermal (or fossil fuel) power plants (TPP) are the major polluters of man's environment, discharging into the atmosphere the basic product of carbon fuel combustion, CO 2 . It is this very gas that accounts for the greenhouse effect causing the global climate warm-up on our planet. A natural solution of the problem of reducing carbon dioxide discharge into the atmosphere lies in power saving, thus reducing the amount of the fuel burnt. This approach can be justified from any standpoint, both economically and ecologically. The ideal way of solving the problem would be to completely give up burning carbon-containing fuel, such as coal, petroleum products, and other power resources of organic nature. This work is intended to outline the ways of reducing consumption of fuel by TPP and, consequently, of reducing their discharging into the atmosphere the gases producing the greenhouse effect. One of the ways lies in changing the thermophysical characteristics of the working medium, which becomes possible if we can modify the conventional working medium, that is water, or can use some working medium with quite different thermophysical properties. The article dwells on various technological ways providing for a practical solution of the problem, such as the Kalina cycle; modification of water properties by way of magneto-hydrodynamic resonance (MHD resonance); and employing, in the thermodynamic cycle of Thermal Power Plants, liquids boiling at temperatures which are lower than that of the environment

  16. Numerical investigation of the thermal and electrical performances for combined solar photovoltaic/thermal (PV/T) modules based on internally extruded fin flow channel

    Science.gov (United States)

    Deng, Y. C.; Li, Q. P.; Wang, G. J.

    2017-11-01

    A solar photovoltaic/thermal (PV/T) module based on internally extruded fin flow channel was investigated numerically in this paper. First of all, the structures of the thin plate heat exchanger and the PV/T module were presented. Then, a numerical model of the PV/T module considering solar irradiation, fluid flow and heat transfer was developed to analyze the performance of the module. Finally, the steady electrical and thermal efficiencies of the PV/T module at different inlet water temperatures and mass flow rates were achieved. These numerical results supply theory basis for practical application of the PV/T module.

  17. High-power electronics thermal management with intermittent multijet sprays

    International Nuclear Information System (INIS)

    Panão, Miguel R.O.; Correia, André M.; Moreira, António L.N.

    2012-01-01

    Thermal management plays a crucial role in the development of high-power electronics devices, e.g. in electric vehicles. The greatest energy demands occur during power peaks, implying dynamic thermal losses within the vehicle’s driving cycle. Therefore, the need for devising intelligent thermal management systems able to efficiently respond to these power peaks has become a technological challenge. Experiments have been performed with methanol in order to quantify the maximum heat flux removed by a multijet spray to keep the 4 cm 2 surface temperature stabilized and below the threshold of 125 °C. A multijet atomization strategy consists in producing a spray through the multiple and simultaneous impact of N j cylindrical jets. Moreover, the spray intermittency is expressed through the duty cycle (DC), which depends on the frequency and duration of injection. Results evidence that: i) a shorter time between consecutive injection cycles enables a better distribution of the mass flow rate, resulting in larger heat transfer coefficient values, as well as higher cooling efficiencies; ii) compared with continuous sprays, the analysis evidences that an intermittent spray allows benefiting more from phase-change convection. Moreover, the mass flux is mainly affecting heat transfer rather than differences induced in the spray structure by using different multijet configurations. - Highlights: ► Intermittent spray cooling (ISC) is advantageous for intelligent thermal management. ► Distributing the mass flow rate through ISC improves heat transfer. ► Multijet sprays with increasing number of jets have higher heat transfer rates. ► ISC with multijet sprays benefit more from phase-change than continuous sprays.

  18. PS-Modules over Ore Extensions and Skew Generalized Power Series Rings

    Directory of Open Access Journals (Sweden)

    Refaat M. Salem

    2015-01-01

    Full Text Available A right R-module MR is called a PS-module if its socle, SocMR, is projective. We investigate PS-modules over Ore extension and skew generalized power series extension. Let R be an associative ring with identity, MR a unitary right R-module, O=Rx;α,δ Ore extension, MxO a right O-module, S,≤ a strictly ordered additive monoid, ω:S→EndR a monoid homomorphism, A=RS,≤,ω the skew generalized power series ring, and BA=MS,≤RS,≤, ω the skew generalized power series module. Then, under some certain conditions, we prove the following: (1 If MR is a right PS-module, then MxO is a right PS-module. (2 If MR is a right PS-module, then BA is a right PS-module.

  19. Design and characterization of a 200 V, 45 A all-GaN HEMT-based power module

    International Nuclear Information System (INIS)

    Chou, Po-Chien; Cheng, Stone

    2013-01-01

    Emerging gallium nitride (GaN)-based high electron mobility transistor (HEMT) technology has the potential to make lower loss and higher power switching characteristics than those made using traditional silicon (Si) components. This work designed, developed, and tested an all-GaN-based power module. In a 200 V, 45 A module, each switching element comprises three GaN chips in parallel, each of which includes six 2.1 A AlGaN/GaN-on-Si HEMT cells. The cells are wire-bonded in parallel to scale up the power rating. Static I D -V DS characteristics of the module are experimentally obtained over widely varying base plate temperatures, and a low on-state resistance is obtained at an elevated temperature of 125 °C. The fabricated module has a blocking voltage exceeding 200 V at a reverse-leakage current density below 1 mA/mm. Two standard temperature measurements are made to provide a simple means of determining mean cell temperature in the module. Self-heating in AlGaN/GaN HEMTs is studied by electrical analysis and infrared thermography. Electrical analysis provides fast temperature overviews while infrared thermography reveals temperature behavior in selected active regions. The current distribution among cells was acceptable over the measured operating temperature range. The characterization of electrical performance and mechanical performance confirm the potential use of the packaged module for high-power applications. -- Highlights: • This work proposes the design, development, and testing of all-GaN power module. • We develop module package and determine their thermal and electrical properties. • ID-VDS characteristics are obtained over a wide range of base plate temperatures. • Self-heating in GaN HEMTs is studied by electrical analysis and IR thermography

  20. Low Power Operation of Temperature-Modulated Metal Oxide Semiconductor Gas Sensors

    Directory of Open Access Journals (Sweden)

    Javier Burgués

    2018-01-01

    Full Text Available Mobile applications based on gas sensing present new opportunities for low-cost air quality monitoring, safety, and healthcare. Metal oxide semiconductor (MOX gas sensors represent the most prominent technology for integration into portable devices, such as smartphones and wearables. Traditionally, MOX sensors have been continuously powered to increase the stability of the sensing layer. However, continuous power is not feasible in many battery-operated applications due to power consumption limitations or the intended intermittent device operation. This work benchmarks two low-power, duty-cycling, and on-demand modes against the continuous power one. The duty-cycling mode periodically turns the sensors on and off and represents a trade-off between power consumption and stability. On-demand operation achieves the lowest power consumption by powering the sensors only while taking a measurement. Twelve thermally modulated SB-500-12 (FIS Inc. Jacksonville, FL, USA sensors were exposed to low concentrations of carbon monoxide (0–9 ppm with environmental conditions, such as ambient humidity (15–75% relative humidity and temperature (21–27 °C, varying within the indicated ranges. Partial Least Squares (PLS models were built using calibration data, and the prediction error in external validation samples was evaluated during the two weeks following calibration. We found that on-demand operation produced a deformation of the sensor conductance patterns, which led to an increase in the prediction error by almost a factor of 5 as compared to continuous operation (2.2 versus 0.45 ppm. Applying a 10% duty-cycling operation of 10-min periods reduced this prediction error to a factor of 2 (0.9 versus 0.45 ppm. The proposed duty-cycling powering scheme saved up to 90% energy as compared to the continuous operating mode. This low-power mode may be advantageous for applications that do not require continuous and periodic measurements, and which can tolerate

  1. Low Power Operation of Temperature-Modulated Metal Oxide Semiconductor Gas Sensors.

    Science.gov (United States)

    Burgués, Javier; Marco, Santiago

    2018-01-25

    Mobile applications based on gas sensing present new opportunities for low-cost air quality monitoring, safety, and healthcare. Metal oxide semiconductor (MOX) gas sensors represent the most prominent technology for integration into portable devices, such as smartphones and wearables. Traditionally, MOX sensors have been continuously powered to increase the stability of the sensing layer. However, continuous power is not feasible in many battery-operated applications due to power consumption limitations or the intended intermittent device operation. This work benchmarks two low-power, duty-cycling, and on-demand modes against the continuous power one. The duty-cycling mode periodically turns the sensors on and off and represents a trade-off between power consumption and stability. On-demand operation achieves the lowest power consumption by powering the sensors only while taking a measurement. Twelve thermally modulated SB-500-12 (FIS Inc. Jacksonville, FL, USA) sensors were exposed to low concentrations of carbon monoxide (0-9 ppm) with environmental conditions, such as ambient humidity (15-75% relative humidity) and temperature (21-27 °C), varying within the indicated ranges. Partial Least Squares (PLS) models were built using calibration data, and the prediction error in external validation samples was evaluated during the two weeks following calibration. We found that on-demand operation produced a deformation of the sensor conductance patterns, which led to an increase in the prediction error by almost a factor of 5 as compared to continuous operation (2.2 versus 0.45 ppm). Applying a 10% duty-cycling operation of 10-min periods reduced this prediction error to a factor of 2 (0.9 versus 0.45 ppm). The proposed duty-cycling powering scheme saved up to 90% energy as compared to the continuous operating mode. This low-power mode may be advantageous for applications that do not require continuous and periodic measurements, and which can tolerate slightly higher

  2. Exergetic comparison of two different cooling technologies for the power cycle of a thermal power plant

    International Nuclear Information System (INIS)

    Blanco-Marigorta, Ana M.; Victoria Sanchez-Henriquez, M.; Pena-Quintana, Juan A.

    2011-01-01

    Exergetic analysis is without any doubt a powerful tool for developing, evaluating and improving an energy conversion system. In the present paper, two different cooling technologies for the power cycle of a 50 MWe solar thermal power plant are compared from the exergetic viewpoint. The Rankine cycle design is a conventional, single reheat design with five closed and one open extraction feedwater heaters. The software package GateCycle is used for the thermodynamic simulation of the Rankine cycle model. The first design configuration uses a cooling tower while the second configuration uses an air cooled condenser. With this exergy analysis we identify the location, magnitude and the sources or thermodynamic inefficiencies in this thermal system. This information is very useful for improving the overall efficiency of the power system and for comparing the performance of both technologies.

  3. Designing a solar powered Stirling heat engine based on multiple criteria: Maximized thermal efficiency and power

    International Nuclear Information System (INIS)

    Ahmadi, Mohammad Hossein; Sayyaadi, Hoseyn; Dehghani, Saeed; Hosseinzade, Hadi

    2013-01-01

    Highlights: • Thermodynamic model of a solar-dish Stirling engine was presented. • Thermal efficiency and output power of the engine were simultaneously maximized. • A final optimal solution was selected using several decision-making methods. • An optimal solution with least deviation from the ideal design was obtained. • Optimal solutions showed high sensitivity against variation of system parameters. - Abstract: A solar-powered high temperature differential Stirling engine was considered for optimization using multiple criteria. A thermal model was developed so that the output power and thermal efficiency of the solar Stirling system with finite rate of heat transfer, regenerative heat loss, conductive thermal bridging loss, finite regeneration process time and imperfect performance of the dish collector could be obtained. The output power and overall thermal efficiency were considered for simultaneous maximization. Multi-objective evolutionary algorithms (MOEAs) based on the NSGA-II algorithm were employed while the solar absorber temperature and the highest and lowest temperatures of the working fluid were considered the decision variables. The Pareto optimal frontier was obtained and a final optimal solution was also selected using various decision-making methods including the fuzzy Bellman–Zadeh, LINMAP and TOPSIS. It was found that multi-objective optimization could yield results with a relatively low deviation from the ideal solution in comparison to the conventional single objective approach. Furthermore, it was shown that, if the weight of thermal efficiency as one of the objective functions is considered to be greater than weight of the power objective, lower absorber temperature and low temperature ratio should be considered in the design of the Stirling engine

  4. Applications of laser diagnostics to thermal power plants and engines

    International Nuclear Information System (INIS)

    Deguchi, Y.; Kamimoto, T.; Wang, Z.Z.; Yan, J.J.; Liu, J.P.; Watanabe, H.; Kurose, R.

    2014-01-01

    The demands for lowering the burdens on the environment will continue to grow steadily. It is important to monitor controlling factors in order to improve the operation of industrial thermal systems. In engines, exhaust gas temperature and concentration distributions are important factors in nitrogen oxides (NO x ), total hydrocarbon (THC) and particulate matter (PM) emissions. Coal and fly ash contents are parameters which can be used for the control of coal-fired thermal power plants. Monitoring of heavy metals such as Hg is also important for pollution control. In this study, the improved laser measurement techniques using computed tomography-tunable diode laser absorption spectroscopy (CT-TDLAS), low pressure laser-induced breakdown spectroscopy (LIBS), and laser breakdown time-of-flight mass spectrometry (LB-TOFMS) have been developed and applied to measure 2D temperature and species concentrations in engine exhausts, coal and fly ash contents, and trace species measurement. The 2D temperature and NH 3 concentration distributions in engine exhausts were successfully measured using CT-TDLAS. The elemental contents of size-segregated particles were measured and the signal stability increased using LIBS with the temperature correction method. The detection limit of trace species measurement was enhanced using low pressure LIBS and LB-TOFMS. The detection limit of Hg can be enhanced to 3.5 ppb when employing N 2 as the buffer gas using low pressure LIBS. Hg detection limit was about 0.82 ppb using 35 ps LB-TOFMS. Compared to conventional measurement methods laser diagnostics has high sensitivity, high response and non-contact features for actual industrial systems. With these engineering developments, transient phenomena such as start-ups in thermal systems can be evaluated to improve the efficiency of these thermal processes. - Highlights: • Applicability of newly developed laser diagnostics was demonstrated for the improvement of thermal power plants and

  5. Development of core thermal-hydraulics module for intelligent reactor design system (IRDS)

    International Nuclear Information System (INIS)

    Kugo, Teruhiko; Nakagawa, Masayuki; Fujii, Sadao.

    1994-08-01

    We have developed an innovative reactor core thermal-hydraulics module where a designer can easily and efficiently evaluate his design concept of a new type reactor in the thermal-hydraulics field. The main purpose of this module is to decide a feasible range of basic design parameters of a reactor core in a conceptual design stage of a new type reactor. The module is to be implemented in Intelligent Reactor Design System (IRDS). The module has the following characteristics; 1) to deal with several reactor types, 2) four thermal hydraulics and fuel behavior analysis codes are installed to treat different type of reactors and design detail, 3) to follow flexibly modification of a reactor concept, 4) to provide analysis results in an understandable way so that a designer can easily evaluate feasibility of his concept, and so on. The module runs on an engineering workstation (EWS) and has a user-friendly man-machine interface on a pre- and post-processing. And it is equipped with a function to search a feasible range called as Design Window, for two design parameters by artificial intelligence (AI) technique and knowledge engineering. In this report, structure, guidance for users of an usage of the module and instruction of input data for analysis modules are presented. (author)

  6. Social assessment and location of nuclear and thermal power plants

    International Nuclear Information System (INIS)

    Nemoto, Kazuyasu; Nishio, Mitsuo.

    1979-01-01

    Most of the locations of nuclear and thermal power plants in Japan are depopulated villages with remote rural character, but for the development of such districts, the policy is not yet clearly established, and the appropriate measures are not taken. The living regions of residents and the production regions of enterprises are more and more estranged. Social assessment is the scientific method to perceive the future change due to the installation of power stations. The features particular to the assessment of natural environment and social environment related to the location of power stations are considered, and the technical problems involved in the method of assessment of natural environment are solved, and the actual method of assessment of social environment is developed. Then, the possibility of establishing this method and the problems in its application are investigated. The plan of developing the surroundings of power generation facilities is criticized, and the coordination of the location plan of power companies and the regional projects of municipalities is discussed. Finally, the mechanism of consensus formation concerning the location of power stations is considered, dividing into regional consensus formation and administrative consensus formation, and the possibility of instituting social assessment is examined. (Kako, I.)

  7. Advanced Stirling Radioisotope Generator (ASRG) Thermal Power Model in MATLAB

    Science.gov (United States)

    Wang, Xiao-Yen, J.

    2012-01-01

    This paper presents a one-dimensional steady-state mathematical thermal power model of the ASRG. It aims to provide a guideline of understanding how the ASRG works and what can change its performance. The thermal dynamics and energy balance of the generator is explained using the thermal circuit of the ASRG. The Stirling convertor performance map is used to represent the convertor. How the convertor performance map is coupled in the thermal circuit is explained. The ASRG performance characteristics under i) different sink temperatures and ii) over the years of mission (YOM) are predicted using the one-dimensional model. Two Stirling converter control strategies, i) fixing the hot-end of temperature of the convertor by adjusting piston amplitude and ii) fixing the piston amplitude, were tested in the model. Numerical results show that the first control strategy can result in a higher system efficiency than the second control strategy when the ambient gets warmer or the general-purpose heat source (GPHS) fuel load decays over the YOM. The ASRG performance data presented in this paper doesn't pertain to the ASRG flight unit. Some data of the ASRG engineering unit (EU) and flight unit that are available in public domain are used in this paper for the purpose of numerical studies.

  8. Reliable and repeatable bonding technology for high temperature automotive power modules for electrified vehicles

    International Nuclear Information System (INIS)

    Yoon, Sang Won; Shiozaki, Koji; Glover, Michael D; Mantooth, H Alan

    2013-01-01

    This paper presents the feasibility of highly reliable and repeatable copper–tin transient liquid phase (Cu–Sn TLP) bonding as applied to die attachment in high temperature operational power modules. Electrified vehicles are attracting particular interest as eco-friendly vehicles, but their power modules are challenged because of increasing power densities which lead to high temperatures. Such high temperature operation addresses the importance of advanced bonding technology that is highly reliable (for high temperature operation) and repeatable (for fabrication of advanced structures). Cu–Sn TLP bonding is employed herein because of its high remelting temperature and desirable thermal and electrical conductivities. The bonding starts with a stack of Cu–Sn–Cu metal layers that eventually transforms to Cu–Sn alloys. As the alloys have melting temperatures (Cu 3 Sn: > 600 °C, Cu 6 Sn 5 : > 400 °C) significantly higher than the process temperature, the process can be repeated without damaging previously bonded layers. A Cu–Sn TLP bonding process was developed using thin Sn metal sheets inserted between copper layers on silicon die and direct bonded copper substrates, emulating the process used to construct automotive power modules. Bond quality is characterized using (1) proof-of-concept fabrication, (2) material identification using scanning electron microscopy and energy-dispersive x-ray spectroscopy analysis, and (3) optical analysis using optical microscopy and scanning acoustic microscope. The feasibility of multiple-sided Cu–Sn TLP bonding is demonstrated by the absence of bondline damage in multiple test samples fabricated with double- or four-sided bonding using the TLP bonding process. (paper)

  9. Preapplication safety evaluation report for the Power Reactor Innovative Small Module (PRISM) liquid-metal reactor

    International Nuclear Information System (INIS)

    Donoghue, J.E.; Donohew, J.N.; Golub, G.R.; Kenneally, R.M.; Moore, P.B.; Sands, S.P.; Throm, E.D.; Wetzel, B.A.

    1994-02-01

    This preapplication safety evaluation report (PSER) presents the results of the preapplication desip review for die Power Reactor Innovative Small Module (PRISM) liquid-mew (sodium)-cooled reactor, Nuclear Regulatory Commission (NRC) Project No. 674. The PRISM conceptual desip was submitted by the US Department of Energy in accordance with the NRC's ''Statement of Policy for the Regulation of Advanced Nuclear Power Plants'' (51 Federal Register 24643). This policy provides for the early Commission review and interaction with designers and licensees. The PRISM reactor desip is a small, modular, pool-type, liquid-mew (sodium)-cooled reactor. The standard plant design consists of dim identical power blocks with a total electrical output rating of 1395 MWe- Each power block comprises three reactor modules, each with a thermal rating of 471 MWt. Each module is located in its own below-grade silo and is co to its own intermediate heat transport system and steam generator system. The reactors utilize a metallic-type fuel, a ternary alloy of U-Pu-Zr. The design includes passive reactor shutdown and passive decay heat removal features. The PSER is the NRC's preliminary evaluation of the safety features in the PRISM design, including the projected research and development programs required to support the design and the proposed testing needs. Because the NRC review was based on a conceptual design, the PSER did not result in an approval of the design. Instead it identified certain key safety issues, provided some guidance on applicable licensing criteria, assessed the adequacy of the preapplicant's research and development programs, and concluded that no obvious impediments to licensing the PRISM design had been identified

  10. Numerical Investigation of the Thermal Management Performance of MEPCM Modules for PV Applications

    Directory of Open Access Journals (Sweden)

    Chao-Yang Huang

    2013-08-01

    Full Text Available The efficiency of photovoltaic modules decreases as the cell temperature increases. It is necessary to have an adequate thermal management mechanism for a photovoltaic module, especially when combined with a building construction system. This study aims to investigate via computational fluid dynamics simulations the heat transfer characteristics and thermal management performance of microencapsulated phase change material modules for photovoltaic applications under temporal variations of daily solar irradiation. The results show that the aspect ratio of the microencapsulated phase change material layer has significant effects on the heat transfer characteristics and the overall thermal performance of the two cases examined with different melting points (26 °C and 34 °C are approximately the same.

  11. Thermal power plants in the Oslofjord district - Recipient evaluations

    International Nuclear Information System (INIS)

    Boehle, B.; Danielssen, D.; Tveite, S.; Haugen, I.; Nilsen, G.; Audunson, T.; Rye, H.; Thendrup, A.

    1975-11-01

    The results presented in a series of reports from the three institutes concerning the physical characteristics of the waters in the vicinoty of five possible sites for thermal (including nuclear) power plants in the Oslofjord district, and the spreading and effects of thermal effluents on the biological state and resources of these waters, are summarised, and an evaluation of the relative suitability of these sites is made. The sites are ranked as follows:- 1. Naverfjorden or, 2. Langangsfjorden - Saga, with effluent release to the Naverfjord region in both cases; 3. Vardeaasen; 4. Hurum; 5; Brenntangen. The possible intake - outlet arrangements are ranked as follows:-1. Deep intake - surface outlet, 2. Deep intake - deep outlet, or surface intake - surface outlet, 3. Surface intake - deep outlet. (JIW)

  12. Reactive power influence on the thermal cycling of multi-MW wind power inverter

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2012-01-01

    converter system are first presented at different wind speeds. Furthermore, the interaction between paralleled converter systems in a wind park is also considered and analyzed. By controlling the reactive power circulated among paralleled converters, a new concept is then proposed to stabilize the thermal...

  13. Strategies for emission reduction from thermal power plants.

    Science.gov (United States)

    Prisyazhniuk, Vitaly A

    2006-07-01

    Major polluters of man's environment are thermal power stations (TPS) and power plants, which discharge into the atmosphere the basic product of carbon fuel combustion, CO2, which results in a build-up of the greenhouse effect and global warm-up of our planet's climate. This paper is intended to show that the way to attain environmental safety of the TPS and to abide by the decisions of the Kyoto Protocol lies in raising the efficiency of the heat power stations and reducing their fuel consumption by using nonconventional thermal cycles. Certain equations have been derived to define the quantitative interrelationship between the growth of efficiency of the TPS, decrease in fuel consumption and reduction of discharge of dust, fuel combustion gases, and heat into the environment. New ideas and new technological approaches that result in raising the efficiency of the TPS are briefly covered: magneto-hydrodynamic resonance, the Kalina cycle, and utilizing the ambient heat by using, as the working medium, low-boiling substances.

  14. Cooling problems of thermal power plants. Physical model studies

    International Nuclear Information System (INIS)

    Neale, L.C.

    1975-01-01

    The Alden Research Laboratories of Worcester Polytechnic Institute has for many years conducted physical model studies, which are normally classified as river or structural hydraulic studies. Since 1952 one aspect of these studies has involved the heated discharge from steam power plants. The early studies on such problems concentrated on improving the thermal efficiency of the system. This was accomplished by minimizing recirculation and by assuring full use of available cold water supplies. With the growing awareness of the impact of thermal power generation on the environment attention has been redirected to reducing the effect of heated discharges on the biology of the receiving body of water. More specifically the efforts of designers and operators of power plants are aimed at meeting or complying with standards established by various governmental agencies. Thus the studies involve developing means of minimizing surface temperatures at an outfall or establishing a local area of higher temperature with limits specified in terms of areas or distances. The physical models used for these studies have varied widely in scope, size, and operating features. These models have covered large areas with both distorted geometric scales and uniform dimensions. Instrumentations has also varied from simple mercury thermometers to computer control and processing of hundreds of thermocouple indicators

  15. Thermal-hydraulic interfacing code modules for CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.S.; Gold, M.; Sills, H. [Ontario Hydro Nuclear, Toronto (Canada)] [and others

    1997-07-01

    The approach for CANDU reactor safety analysis in Ontario Hydro Nuclear (OHN) and Atomic Energy of Canada Limited (AECL) is presented. Reflecting the unique characteristics of CANDU reactors, the procedure of coupling the thermal-hydraulics, reactor physics and fuel channel/element codes in the safety analysis is described. The experience generated in the Canadian nuclear industry may be useful to other types of reactors in the areas of reactor safety analysis.

  16. Thermal-hydraulic interfacing code modules for CANDU reactors

    International Nuclear Information System (INIS)

    Liu, W.S.; Gold, M.; Sills, H.

    1997-01-01

    The approach for CANDU reactor safety analysis in Ontario Hydro Nuclear (OHN) and Atomic Energy of Canada Limited (AECL) is presented. Reflecting the unique characteristics of CANDU reactors, the procedure of coupling the thermal-hydraulics, reactor physics and fuel channel/element codes in the safety analysis is described. The experience generated in the Canadian nuclear industry may be useful to other types of reactors in the areas of reactor safety analysis

  17. POWER ELECTRONIC SYSTEM FOR POWER ELECTRIC VEHICLES WITH ALGORITHMS OF SYNCHRONOUS MODULATION

    Directory of Open Access Journals (Sweden)

    Oleschuk V.

    2014-04-01

    Full Text Available Schemes of synchronous space-vector modulation have been adapted for control of split-phase drive for electric vehicle with open-end windings of induction motor, supplied by several voltage source inverters. MATLAB-based simulation of processes in this system has been executed. It has been shown, that the use of algorithms of synchronous modulation provides symmetry of phase voltage waveforms for any ratio between the switching frequency and fundamental frequency, and for any voltage magnitudes of dc-sources. Spectra of the phase voltage of system do not contain even harmonics and subharmonics (of the fundamental frequency, which is especially important for drives for the medium-power and high-power electric vehicles.

  18. Temperature measurement by thermal strain imaging with diagnostic power ultrasound, with potential for thermal index determination.

    Science.gov (United States)

    Liang, Hai-Dong; Zhou, Li-Xia; Wells, Peter N T; Halliwell, Michael

    2009-05-01

    Over the years, there has been a substantial increase in acoustic exposure in diagnostic ultrasound as new imaging modalities with higher intensities and frame rates have been introduced; and more electronic components have been packed into the probe head, so that there is a tendency for it to become hotter. With respect to potential thermal effects, including those which may be hazardous occurring during ultrasound scanning, there is a correspondingly growing need for in vivo techniques to guide the operator as to the actual temperature rise occurring in the examined tissues. Therefore, an in vivo temperature estimator would be of considerable practical value. The commonly-used method of tissue thermal index (TI) measurement with a hydrophone in water could underestimate the actual value of TI (in one report by as much as 2.9 times). To obtain meaningful results, it is necessary to map the temperature elevation in 2-D (or 3-D) space. We present methodology, results and validation of a 2-D spatial and temporal thermal strain ultrasound temperature estimation technique in phantoms, and its apparently novel application in tracking the evolution of heat deposition at diagnostic exposure levels. The same ultrasound probe is used for both transmission and reception. The displacement and thermal strain estimation methods are similar to those used in high-intensity focused ultrasound thermal monitoring. The use of radiofrequency signals permits the application of cross correlation as a similarity measurement for tracking feature displacement. The displacement is used to calculate the thermal strain directly related to the temperature rise. Good agreement was observed between the temperature rise and the ultrasound power and scan duration. Thermal strain up to 1.4% was observed during 4000-s scan. Based on the results obtained for the temperature range studied in this work, the technique demonstrates potential for applicability in phantom (and possibly in vivo tissue

  19. A Battery Power Bank with Series-Connected Buck–Boost-Type Battery Power Modules

    Directory of Open Access Journals (Sweden)

    Tsung-Hsi Wu

    2017-05-01

    Full Text Available The operation of a battery power bank with series-connected buck–boost-type battery power modules (BPMs was investigated in this study. Each BPM consisted of a battery pack with an associated buck–boost converter for individually controlling battery currents. With a proposed discharging scenario, load voltage regulation with charge equalization among batteries was performed by controlling the battery currents in accordance with their state-of-charges (SOCs estimated by real-time battery-loaded voltages detected under the same operating condition. In addition, the fault tolerance was executed to isolate exhausted or faulty batteries from the battery power bank without interrupting the system operation. Experiments were conducted to verify the effectiveness of the discharging scenario for a laboratory battery power bank with four series buck–boost BPMs.

  20. A numerical simulation package for analysis of neutronics and thermal fluids of space nuclear power and propulsion systems

    International Nuclear Information System (INIS)

    Anghaie, S.; Feller, G.J.; Peery, S.D.; Parsley, R.C.

    1993-01-01

    A system of computer codes for engineering simulation and in-depth analysis of nuclear and thermal fluid design of nuclear thermal rockets is developed. The computational system includes a neutronic solver package, a thermal fluid solver package and a propellant and materials property package. The Rocket Engine Transient Simulation (ROCETS) system code is incorporated with computational modules specific to nuclear powered engines. ROCETS features a component based performance architecture that interfaces component modules into the user designed configuration, interprets user commands, creates an executable FORTRAN computer program, and executes the program to provide output to the user. Basic design features of the Pratt ampersand Whitney XNR2000 nuclear rocket concept and its operational performance are analyzed and simulated

  1. Development of a new lower hybrid antenna module using a poloidal power divider

    International Nuclear Information System (INIS)

    Maebara, S.; Imai, T.; Seki, M.; Suganuma, K.; Goniche, M.; Bibet, Ph.; Berio, S.; Brossaud, J.; Rey, G.; Tonon, G.

    1997-03-01

    A realistic antenna module using a poloidal divider for lower hybrid current drive (LHCD) experiment, is modelled and fabricated. In this antenna module test II, three types of poloidal dividers, which split the power in 3, are tested. (author)

  2. Extended Pulse-Powered Humidity-Freeze Cycling for Testing Module-Level Power Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, Peter L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kempe, Michael D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Repins, Ingrid L [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-28

    An EMI suppression capacitor (polypropylene film type) failed by 'popcorning' due to vapor outgassing in pulse powered humidity-freeze cycles. No shorts or shunts could be detected despite mildly corroded metallization visible in the failed capacitor. Humidity-freeze cycling is optimized to break into moisture barriers. However, further studies will be required on additional module level power electronic (MLPE) devices to optimize the stress testing for condensation to precipitate any weakness to short circuiting and other humidity/bias failure modes.

  3. SSTAC/ARTS review of the draft Integrated Technology Plan (ITP). Volume 3: Space power and thermal management

    International Nuclear Information System (INIS)

    1991-06-01

    Viewgraphs of briefings from the SSTAC/ARTS review of the draft integrated technology plan on thermal power and thermal management are presented. Topics covered include: space energy conversion research and technology; space photovoltaic energy conversion; chemical energy conversion and storage; thermal energy conversion; power management; thermal management; space nuclear power; high capacity power; surface power and thermal management; space platforms power and thermal management; and project SELENE

  4. Prognostics Approach for Power MOSFET Under Thermal-Stress

    Science.gov (United States)

    Galvan, Jose Ramon Celaya; Saxena, Abhinav; Kulkarni, Chetan S.; Saha, Sankalita; Goebel, Kai

    2012-01-01

    The prognostic technique for a power MOSFET presented in this paper is based on accelerated aging of MOSFET IRF520Npbf in a TO-220 package. The methodology utilizes thermal and power cycling to accelerate the life of the devices. The major failure mechanism for the stress conditions is dieattachment degradation, typical for discrete devices with leadfree solder die attachment. It has been determined that dieattach degradation results in an increase in ON-state resistance due to its dependence on junction temperature. Increasing resistance, thus, can be used as a precursor of failure for the die-attach failure mechanism under thermal stress. A feature based on normalized ON-resistance is computed from in-situ measurements of the electro-thermal response. An Extended Kalman filter is used as a model-based prognostics techniques based on the Bayesian tracking framework. The proposed prognostics technique reports on preliminary work that serves as a case study on the prediction of remaining life of power MOSFETs and builds upon the work presented in [1]. The algorithm considered in this study had been used as prognostics algorithm in different applications and is regarded as suitable candidate for component level prognostics. This work attempts to further the validation of such algorithm by presenting it with real degradation data including measurements from real sensors, which include all the complications (noise, bias, etc.) that are regularly not captured on simulated degradation data. The algorithm is developed and tested on the accelerated aging test timescale. In real world operation, the timescale of the degradation process and therefore the RUL predictions will be considerable larger. It is hypothesized that even though the timescale will be larger, it remains constant through the degradation process and the algorithm and model would still apply under the slower degradation process. By using accelerated aging data with actual device measurements and real

  5. Availability of thermal power plants 1977-1986

    International Nuclear Information System (INIS)

    Nitsch, D.; Schmitz, H.

    1987-01-01

    To get a picture of power plant availability and its influencing factors, availability data have been acquired and evaluated by VGB according to different design and operation parameters since 1970. The present volume is the 16th annual statistics since 1970. It covers the decade of 1977 to 1986 and contains availability data of 384 power plants in Germany and abroad, with a total of 94.896 MW and 3.768 plant years. Data are presented on fossil-fuelled units, units with a combined gas/steam cycle, nuclear power plants and gas turbine systems, with further sub-categories according to unit size, fuel, type, years of operation, and operating regime. German plants are reviewed separately. All power data are gross data measured at the generator terminals. For a comparative evaluation, the data of 1986 are supplemented by yearly averages since 1977 and averages for the decade from 1977 to 1986. Since 1978, nonavailability data are categorized as 'unscheduled' and 'scheduled' nonavailabilities. For availability data of 1970 to 1976, see the VGB publication 'Availability of thermal power plants, 1970 to 1981'. (orig./UA) [de

  6. Hybrid wind power balance control strategy using thermal power, hydro power and flow batteries

    OpenAIRE

    Gelažanskas, Linas; Baranauskas, Audrius; Gamage, Kelum A.A.; Ažubalis, Mindaugas

    2016-01-01

    The increased number of renewable power plants pose threat to power system balance. Their intermittent nature makes it very difficult to predict power output, thus either additional reserve power plants or new storage and control technologies are required. Traditional spinning reserve cannot fully compensate sudden changes in renewable energy power generation. Using new storage technologies such as flow batteries, it is feasible to balance the variations in power and voltage within very short...

  7. Application of the thermal efficiency analysis software 'EgWin' at existing power plants

    International Nuclear Information System (INIS)

    Koda, E.; Takahashi, T.; Nakao, Y.

    2008-01-01

    'EgWin' is the general purpose software to analyze a thermal efficiency of power system developed in CRIEPI. This software has been used to analyze the existing power generation unit of 30 or more, and the effectiveness has been confirmed. In thermal power plants, it was used for the clarification of the thermal efficiency decrease factor and the quantitative estimation of the influence that each factor gave to the thermal efficiency of the plant. Also it was used for the quantitative estimation of the effect by the operating condition change and the facility remodeling in thermal power, atomic energy, and geothermal power plants. (author)

  8. Nuclear power plant thermal-hydraulic performance research program plan

    International Nuclear Information System (INIS)

    1988-07-01

    The purpose of this program plan is to present a more detailed description of the thermal-hydraulic research program than that provided in the NRC Five-Year Plan so that the research plan and objectives can be better understood and evaluated by the offices concerned. The plan is prepared by the Office of Nuclear Regulatory Research (RES) with input from the Office of Nuclear Reactor Regulation (NRR) and updated periodically. The plan covers the research sponsored by the Reactor and Plant Systems Branch and defines the major issues (related to thermal-hydraulic behavior in nuclear power plants) the NRC is seeking to resolve and provides plans for their resolution; relates the proposed research to these issues; defines the products needed to resolve these issues; provides a context that shows both the historical perspective and the relationship of individual projects to the overall objectives; and defines major interfaces with other disciplines (e.g., structural, risk, human factors, accident management, severe accident) needed for total resolution of some issues. This plan addresses the types of thermal-hydraulic transients that are normally considered in the regulatory process of licensing the current generation of light water reactors. This process is influenced by the regulatory requirements imposed by NRC and the consequent need for technical information that is supplied by RES through its contractors. Thus, most contractor programmatic work is administered by RES. Regulatory requirements involve the normal review of industry analyses of design basis accidents, as well as the understanding of abnormal occurrences in operating reactors. Since such transients often involve complex thermal-hydraulic interactions, a well-planned thermal-hydraulic research plan is needed

  9. Simulation and Design of Vehicle Exhaust Power Generation Systems: The Interaction Between the Heat Exchanger and the Thermoelectric Modules

    Science.gov (United States)

    Tao, Cong; Chen, Gang; Mu, Yu; Liu, Lisheng; Zhai, Pengcheng

    2015-06-01

    Vehicle exhaust power generation systems (VEPGS), mainly consisting of a heat exchanger, cooling system, thermoelectric modules (TEMs), and clamping device, have attracted wide interest and attention for power generation from waste heat. In this work, systematical research was conducted to investigate the thermal performance, power output, and thermal stress of a VEPGS by using the multifield coupling method. Different from previous research, this work simulates a model that integrates the heat exchanger and TEMs, focusing on the effect of the TEMs on the thermal performance of the heat exchanger. It is found that the TEMs have a significant effect on the thermal performance of the heat exchanger. When not considering the effects of the TEMs, the hot-end temperature of the TEMs would be seriously underestimated, which would result in underestimation of the power output of the VEPGS and the level of thermal stress of the TEMs. Meanwhile, when considering the effect of the TEMs, the hot-end temperature distribution exhibits significant changes, and its temperature uniformity is significantly improved. The results suggest that, in VEPGS design and optimization, the interaction between the heat exchanger and TEMs should be considered. This study also contributes to a more accurate assessment method for VEPGS design and simulation.

  10. Thermal power blocks with ultra-super-critical steam parameters

    Directory of Open Access Journals (Sweden)

    Aličić Merim M.

    2016-01-01

    Full Text Available New generation of thermal power plants are required to have increased utilization rates, in addition to reduced emissions of pollutants, in order to reach optimal solutions, from both technical and economic point of view. One way to achieve greater utilization efficiency is operation of the plant at super critical (SC or ultra super critical steam parameters (USC. However, achieving high parameters depends on use of new materials, which have better properties at high temperatures and pressures, use of new welding technologies and by solving the problem of corrosion. The paper gives an overview of some of the plants with these parameters.

  11. New water intake systems for thermal and nuclear power plants

    International Nuclear Information System (INIS)

    Ishchuk, T.B.; Samodel'nikov, B.T.

    1989-01-01

    Problems arising during design of water intake and spillway structures for the auxiliary water supply system of thermal and nuclear power plants connected with the provision of their reliable operation and with the effect on the temperature condition of reservoirs and their ecology are investigated. Design providing for the connection of intake channel and catch drain for a through (transition) channel and supplying a water transition flow by ejecting water outputs is suggested. The variant considered is effective for seas, lakes and reservoirs with adverse conditions for natural cooling and it is suitable for regions with seismicity up to 5-6 balls

  12. Vibration monitoring and fault diagnostics of a thermal power plant

    International Nuclear Information System (INIS)

    Hafeez, T.; Ghani, R.; Chohan, G.Y.; Amir, M.

    2003-01-01

    A thermal power plant was monitored from HP-turbine to the generator end. The vibration data at different plant locations was obtained with the help of a data collector/analyzer. The spectra of-all locations generate the symptoms for different problems of moderate and high vibration levels like bent shaft, misalignment in the exciter rotor and three couplings, mechanical looseness on generator and exciter sides. The possible causes of these faults are discussed on the basis of presented vibration spectra in this paper. The faults were later on rectified on the basis of this diagnostics. (author)

  13. Parallel Connection of Silicon Carbide MOSFETs for Multichip Power Modules

    DEFF Research Database (Denmark)

    Li, Helong

    challenges from the manufacture and application points of view. The less mature manufacture process limits the yield and the single die size of the SiC MOSFETs, which results a smaller current capability of a single SiC MOSFET die. Consequently, in high current application, the paralleled connections of Si...... connections for the paralleled dies are presented and the source of the transient current imbalance is concluded. To mitigate the transient current imbalance in the traditional DBC layout, a novel DBC layout with split output is proposed. First, the working mechanism of the split output topology is studied...... the current sharing performance among the paralleled SiC MOSFET dies in the power module. The proposed DBC layout is not only limited for SiC MOSFETs, but also for Si IGBTs and other voltage controlled devices. of the circuit mismatch on the paralleled connection of SiC MOSFETs. It reveals the circuit...

  14. Chip-carrier thermal barrier and its impact on lateral thermal lens profile and beam parameter product in high power broad area lasers

    Science.gov (United States)

    Rieprich, J.; Winterfeldt, M.; Kernke, R.; Tomm, J. W.; Crump, P.

    2018-03-01

    High power broad area diode lasers with high optical power density in a small focus spot are in strong commercial demand. For this purpose, the beam quality, quantified via the beam parameter product (BPP), has to be improved. Previous studies have shown that the BPP is strongly affected by current-induced heating and the associated thermal lens formed within the laser stripe. However, the chip structure and module-assembly related factors that regulate the size and the shape of the thermal lens are not well known. An experimental infrared thermographic technique is used to quantify the thermal lens profile in diode lasers operating at an emission wavelength of 910 nm, and the results are compared with finite element method simulations. The analysis indicates that the measured thermal profiles can best be explained when a thermal barrier is introduced between the chip and the carrier, which is shown to have a substantial impact on the BPP and the thermal resistance. Comparable results are observed in further measurements of samples from multiple vendors, and the barrier is only observed for junction-down (p-down) mounting, consistent with the barrier being associated with the GaAs-metal transition.

  15. Pulse Power Modulator development for the CLIC Damping Ring Kickers

    CERN Document Server

    Holma, Janne

    2012-01-01

    The Compact Linear Collider (CLIC) study is exploring the scheme for an electron-positron collider with high luminosity (10-34 – 10-35 cm-2s-1) and a nominal centre-of-mass energy of 3 TeV: CLIC would complement LHC physics in the multi-TeV range. The CLIC design relies on Pre-Damping Rings (PDR) and Damping Rings (DR) to achieve the very low emittance, through synchrotron radiation, needed for the luminosity requirements of CLIC. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the DR kickers must provide extremely flat, high-voltage pulses: the 2 GHz specification called for a 160 ns duration flat-top of 12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 %. In order to meet these demanding specifications, a combination of broadband impedance matching, optimized electrical circuit layout and advanced control techniques is required. A solid-state modulator, the inductive adder, is the most promising approach to meeting the demanding specifications...

  16. Program THEK energy production units of average power and using thermal conversion of solar radiation

    Science.gov (United States)

    1978-01-01

    General studies undertaken by the C.N.R.S. in the field of solar power plants have generated the problem of building energy production units in the medium range of electrical power, in the order of 100 kW. Among the possible solutions, the principle of the use of distributed heliothermal converters has been selected as being, with the current status of things, the most advantageous solution. This principle consists of obtaining the conversion of concentrated radiation into heat by using a series of heliothermal conversion modules scattered over the ground; the produced heat is collected by a heat-carrying fluid circulating inside a thermal loop leading to a device for both regulation and storage.

  17. Integrated packaging of multiple double sided cooling planar bond power modules

    Science.gov (United States)

    Liang, Zhenxian

    2018-04-10

    An integrated double sided cooled power module has one or multiple phase legs configuration including one or more planar power packages, each planar power package having an upper power switch unit and a lower power switch unit directly bonded and interconnected between two insulated power substrates, and further sandwiched between two heat exchangers via direct bonds. A segmented coolant manifold is interposed with the one or more planar power packages and creates a sealed enclosure that defines a coolant inlet, a coolant outlet and a coolant flow path between the inlet and the outlet. A coolant circulates along the flow path to remove heat and increase the power density of the power module.

  18. Thermal energy storage for a space solar dynamic power system

    Science.gov (United States)

    Faget, N. M.; Fraser, W. M., Jr.; Simon, W. E.

    1985-01-01

    In the past, NASA has employed solar photovoltaic devices for long-duration missions. Thus, the Skylab system has operated with a silicon photovoltaic array and a nickel-cadmium electrochemical system energy storage system. Difficulties regarding the employment of such a system for the larger power requirements of the Space Station are related to a low orbit system efficiency and the large weight of the battery. For this reason the employment of a solar dynamic power system (SDPS) has been considered. The primary components of an SDPS include a concentrating mirror, a heat receiver, a thermal energy storage (TES) system, a thermodynamic heat engine, an alternator, and a heat rejection system. The heat-engine types under consideration are a Brayton cycle engine, an organic Rankine cycle engine, and a free-piston/linear-alternator Stirling cycle engine. Attention is given to a system description, TES integration concepts, and a TES technology assessment.

  19. Standard Guide for Specifying Thermal Performance of Geothermal Power Systems

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This guide covers power plant performance terms and criteria for use in evaluation and comparison of geothermal energy conversion and power generation systems. The special nature of these geothermal systems makes performance criteria commonly used to evaluate conventional fossil fuel-fired systems of limited value. This guide identifies the limitations of the less useful criteria and defines an equitable basis for measuring the quality of differing thermal cycles and plant equipment for geothermal resources. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  20. Phytomonitoring of air pollution around a thermal power plant

    Science.gov (United States)

    Agrawal, M.; Agrawal, S. B.

    This study was undertaken in order to assess the impact of air pollutants on vegetation around Obra thermal power plant (1550 M W capacity) in the Mirzapur district of Uttar Pradesh. For this purpose, Mangifera indica, Citrus medico and Bouganvillaea spectabilis plants, most common at all sites, were selected as test plants. Five study sites were selected northeast (prevailing wind) of the thermal power plant. A control site was also selected at a distance of 30 km north of Obra. Responses of plants to pollutants in terms of presence of foliar injury symptoms and changes in chlorophyll, ascorbic acid and S content were measured. These changes were correlated with ambient SO 2 and suspended particulate matter (SPM) concentrations and the amount of dust settled on leaf surfaces. The SO 2 and SPM concentrations were quite high in the immediate vicinity of the power plant. There also exists a direct relationship between the concentration of SPM in air and amount of dust deposited on leaf surfaces. Maximum dust deposition was observed on M. indica plants. The levels of foliar injury, chlorophyll and ascorbic acid were found to decrease and that of S increase in plants around the power plant in comparison to those growing at a control site. The magnitude of such changes was maximum in M. indica and minimum in C. medica. A species specific direct relationship between the increase in the amount of S and decrease in chlorophyll content was observed. The study suggests that differential sensitivity of plants to SO 2 may be used in evaluating the air pollution impact around emission sources and M. indica plants can be used as an indicator plant for quantifying biological changes.

  1. Study on corrosion of thermal power plant condenser tubes

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Abdolreza Rashidi; Zhaam, Ali Akbar [Niroo Research Institute, end of Poonak Bakhtari blvd., Shahrak Ghods, Tehran (Iran)

    2004-07-01

    The aim of this investigation is to study kinds of corrosion mechanisms in thermal power plant condenser tubes. Condenser is a shell and tube heat exchanger in which cooling water flows through its tubes. While the steam from low pressure turbine passes within condenser tubes, it is condensed by cooling water. The exhausted steam from low pressure turbine is condensed on external surface of condenser tubes and heat is transferred to cooling water which flow into tubes. Tubes composition is usually copper-based alloys, stainless steel or titanium. Annual damages due to corrosion cause much cost for replacement and repairing metallic equipment and installations in electric power industry. Because of existence of different contaminants in water and steam cycle, condenser tubes surfaces are exposed to corrosion. Contaminants like oxygen, carbon dioxide, chloride ion and ammonia in water and steam cycle originate several damages such as pitting and crevice corrosion, erosion, galvanic attack, SCC, condensed corrosion, de-alloying in thermal power plant condenser. The paper first states how corrosion damage takes place in condensers and then introduces types of usual alloys used in condensers and also their corrosion behavior. In continuation, a brief explanation is presented about kinds of condenser failures due to corrosion. Then, causes and locations of different mechanisms of corrosion events on condenser tubes and effects of different parameters such as composition, temperature, chloride and sulfide ion concentration, pH, water velocity and biological precipitation are examined and finally protection methods are indicated. Also some photos of tubes specimens related to power plants are studied and described in each case of mentioned mechanisms. (authors)

  2. Renewable energy distributed power system with photovoltaic/ thermal and bio gas power generators

    International Nuclear Information System (INIS)

    Haider, M.U.; Rehman, S.U.

    2011-01-01

    The energy shortage and environmental pollution is becoming an important problem in these days. Hence it is very much important to use renewable power technologies to get rid of these problems. The important renewable energy sources are Bio-Energy, Wind Energy, Hydrogen Energy, Tide Energy, Terrestrial Heat Energy, Solar Energy, Thermal Energy and so on. Pakistan is rich in all these aspects particularly in Solar and Thermal Energies. In major areas of Pakistan like in South Punjab, Sind and Baluchistan the weather condition are very friendly for these types of Renewable Energies. In these areas Solar Energy can be utilized by solar panels in conjunction with thermal panels. The Photovoltaic cells are used to convert Solar Energy directly to Electrical Energy and thermal panels can be uses to convert solar energy into heat energy and this heat energy will be used to drive some turbine to get Electrical Energy. The Solar Energy can be absorbed more efficiently by any given area of Solar Panel if these two technologies can be combined in such a way that they can work together. The first part of this paper shows that how these technologies can be combined. Furthermore it is known to all that photovoltaic/thermal panels depend entirely on weather conditions. So in order to maintain constant power a biogas generator is used in conjunction with these. (author)

  3. Implementation of a cogenerative district heating: optimization of a simulation model for the thermal power demand

    Energy Technology Data Exchange (ETDEWEB)

    Barelli, L.; Bidini, G.; Pinchi, E.M. [Dipartimento di Ingegneria Industriale, Universita degli Studi di Perugia, Perugia (Italy)

    2006-07-01

    The district heating set up with a cogeneration system, concurs to attain energetic, economic and ambient benefits. It also provides to citizens a new service. The project strategy is based on the idea of supplying a portion of the necessary thermal power through a combustion alternative engine in cogeneration modality. It's also interesting to modulate the load with auxiliary boilers fed by natural gas. This solution allows to save primary energy, create a centralization of the energy production, which contributes to the problem of polluting emissions, through the decentralization of the sources. The first step to assess the technical-economic feasibility of a district heating system, based on a cogeneration plant, is to underline and to characterize the energetic request of the basin of user. The objective of the present work is to develop a model that yields an esteem of the hourly thermal load for every days of the heating season of a complex user, represented by a single neighbourhood. To do this, the present work proposes a new method of simulation of the daily and hourly thermal load trend, known only the value of the power installed in the thermal plant for every user, the seasonal hours of the burner operation and the timetable of the heating service distribution, more than the external mean daily temperature trend. The results obtained using this model, have been verified with the data of seasonal consumptions, confirming the validity of the proposed methodology.The above allows to determine, with more precision, the thermal request peak to satisfy, taking in consideration the contemporaneity of the loads, also of different typology, and to carry out a better sizing of the generation plant. (author)

  4. Numerical model analysis of thermal performance for a dye-sensitized solar cell module

    International Nuclear Information System (INIS)

    Chen, Shuanghong; Huang, Yang; Weng, Jian; Fan, Xiaqin; Mo, Lie; Pan, Bin; Dai, Songyuan

    2013-01-01

    Temperature is one of the major factors that influence a dye-sensitized solar cell's (DSC's) photovoltaic efficiency. Temperature control is very important when solar cell modules are designed. In the present paper, a numerical model of a DSC module is built for the simulation of the solar cell's temperature. In this model, energy balance and three methods of heat transfer (conduction, convection, and radiation) are taken into account, and the simulation results are consistent with the experimental results. The influence of wind speeds and interfacial thermal resistance on the temperature inside the DSC modules is discussed in detail based on theoretical analysis. (paper)

  5. Experience in connecting the power generating units of thermal power plants to automatic secondary frequency regulation within the united power system of Russia

    International Nuclear Information System (INIS)

    Zhukov, A. V.; Komarov, A. N.; Safronov, A. N.; Barsukov, I. V.

    2009-01-01

    The principles of central control of the power generating units of thermal power plants by automatic secondary frequency and active power overcurrent regulation systems, and the algorithms for interactions between automatic power control systems for the power production units in thermal power plants and centralized systems for automatic frequency and power regulation, are discussed. The order of switching the power generating units of thermal power plants over to control by a centralized system for automatic frequency and power regulation and by the Central Coordinating System for automatic frequency and power regulation is presented. The results of full-scale system tests of the control of power generating units of the Kirishskaya, Stavropol, and Perm GRES (State Regional Electric Power Plants) by the Central Coordinating System for automatic frequency and power regulation at the United Power System of Russia on September 23-25, 2008, are reported.

  6. A Performance Improvement of Power Supply Module for Safety-related Controller

    International Nuclear Information System (INIS)

    Kim, Jong-Kyun; Yun, Dong-Hwa; Hwang, Sung-Jae; Lee, Myeong-Kyun; Yoo, Kwan-Woo

    2015-01-01

    In this paper, in relation to voltage shortage state when power supply module is a slave mode, the performance improvement by modifying a PFC(Power Factor Correction) circuit is presented. With the modification of the PFC circuit, the performance improvement in respect of the voltage shortage state when the power supply module is a slave mode is checked. As a result, POSAFE-Q PLC can ensure the stability with the redundant power supply module. The purpose of this paper is to improve the redundant performance of power supply module(NSPS-2Q). It is one of components in POSAFE-Q which is a PLC(Programmable Logic Controller) that has been developed for the evaluation of safety-related. Power supply module provides a stable power in order that POSAFE-Q can be operated normally. It is possible to be mounted two power supply modules in POSAFE-Q for a redundant(Master/Slave) function. So that even if a problem occurs in one power supply module, another power supply module will provide a power to POSAFE-Q stably

  7. A Performance Improvement of Power Supply Module for Safety-related Controller

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Kyun; Yun, Dong-Hwa; Hwang, Sung-Jae; Lee, Myeong-Kyun; Yoo, Kwan-Woo [PONUTech Co., Seoul (Korea, Republic of)

    2015-10-15

    In this paper, in relation to voltage shortage state when power supply module is a slave mode, the performance improvement by modifying a PFC(Power Factor Correction) circuit is presented. With the modification of the PFC circuit, the performance improvement in respect of the voltage shortage state when the power supply module is a slave mode is checked. As a result, POSAFE-Q PLC can ensure the stability with the redundant power supply module. The purpose of this paper is to improve the redundant performance of power supply module(NSPS-2Q). It is one of components in POSAFE-Q which is a PLC(Programmable Logic Controller) that has been developed for the evaluation of safety-related. Power supply module provides a stable power in order that POSAFE-Q can be operated normally. It is possible to be mounted two power supply modules in POSAFE-Q for a redundant(Master/Slave) function. So that even if a problem occurs in one power supply module, another power supply module will provide a power to POSAFE-Q stably.

  8. The thermal management of high power light emitting diodes

    Science.gov (United States)

    Hsu, Ming-Seng; Huang, Jen-Wei; Shyu, Feng-Lin

    2012-10-01

    Thermal management had an important influence not only in the life time but also in the efficiency of high power light emitting diodes (HPLEDs). 30 watts in a single package have become standard to the industrial fabricating of HPLEDs. In this study, we fabricated both of the AlN porous films, by vacuum sputtering, soldered onto the HPLEDs lamp to enhance both of the heat transfer and heat dissipation. In our model, the ceramic enables transfer the heat from electric device to the aluminum plate quickly and the porous increase the quality of the thermal dissipation between the PCB and aluminum plate, as compared to the industrial processing. The ceramic films were characterized by several subsequent analyses, especially the measurement of real work temperature. The X-Ray diffraction (XRD) diagram analysis reveals those ceramic phases were successfully grown onto the individual substrates. The morphology of ceramic films was investigated by the atomic force microscopy (AFM). The results show those porous films have high thermal conduction to the purpose. At the same time, they had transferred heat and limited work temperature, about 70°, of HPLEDs successfully.

  9. Availability of thermal power plants 1976-1985

    International Nuclear Information System (INIS)

    Nitsch, D.; Schmitz, H.

    1986-01-01

    This assessment is the 15th annual assessment since 1970. It covers the decade 1976 to 1985 and contains the availability figures for 395 power stations in Germany and abroad with an output of about 93,750 MW and 3,642 years of power station operation. The availability figures of fossil fired units, combined units (plant with combined gas/steam circuit), nuclear power stations and gas turbine plants are given, which are classified according to unit size, fuel, type of construction, age and method of use. The German plants are covered separately. All output figures are gross figures (output at the generator terminals). For comparison purposes, apart for the results of 1985, the annual values determined since 1976 and the mean values for the decade 1976-1985 are given. The non-availability is divided into faults and planned outages since 1978. Availability figures for the years 1970 to 1975 can be found in the VGB assessment 'Availability of thermal power plants 1970-1981'. (orig./GL) [de

  10. Experimental research of limits for thermal modulation transfer function

    Directory of Open Access Journals (Sweden)

    Tomić Ljubiša D.

    2009-01-01

    Full Text Available The paper presented testing of surface defects by pulse video thermography techniques. Such techniques rely on transient infrared radiation from the sample heated by the short duration flux initiated by flesh. Experimental measurements are realized by infrared sensor (FLIR camera. Testing results are considered for the samples with controlled designed defects beyond observed surfaces. The effects of response through the transparent wall are measured as infrared visible radiance. Researches with controlled samples are performed to verify visibility threshold of defect dimensions and forms, for possible use as modulation transfer function of defects hidden beyond the surfaces of thin metal walls. Dimensionless coefficients are derived for method estimations as the results from experimental research.

  11. Generator module architecture for a large solid oxide fuel cell power plant

    Science.gov (United States)

    Gillett, James E.; Zafred, Paolo R.; Riggle, Matthew W.; Litzinger, Kevin P.

    2013-06-11

    A solid oxide fuel cell module contains a plurality of integral bundle assemblies, the module containing a top portion with an inlet fuel plenum and a bottom portion receiving air inlet feed and containing a base support, the base supports dense, ceramic exhaust manifolds which are below and connect to air feed tubes located in a recuperator zone, the air feed tubes passing into the center of inverted, tubular, elongated, hollow electrically connected solid oxide fuel cells having an open end above a combustion zone into which the air feed tubes pass and a closed end near the inlet fuel plenum, where the fuel cells comprise a fuel cell stack bundle all surrounded within an outer module enclosure having top power leads to provide electrical output from the stack bundle, where the fuel cells operate in the fuel cell mode and where the base support and bottom ceramic air exhaust manifolds carry from 85% to all 100% of the weight of the stack, and each bundle assembly has its own control for vertical and horizontal thermal expansion control.

  12. Design and modeling of low temperature solar thermal power station

    International Nuclear Information System (INIS)

    Shankar Ganesh, N.; Srinivas, T.

    2012-01-01

    Highlights: ► The optimum conditions are different for efficiency and power conditions. ► The current model works up to a maximum separator temperature of 150 °C. ► The turbine concentration influences the high pressure. ► High solar beam radiation and optimized cycle conditions give low collector cost. -- Abstract: During the heat recovery in a Kalina cycle, a binary aqua–ammonia mixture changes its state from liquid to vapor, the more volatile ammonia vaporizes first and then the water starts vaporization to match temperature profile of the hot fluid. In the present work, a low temperature Kalina cycle has been investigated to optimize the heat recovery from solar thermal collectors. Hot fluid coming from solar parabolic trough collector with vacuum tubes is used to generate ammonia rich vapor in a boiler for power generation. The turbine inlet conditions are optimized to match the variable hot fluid temperature with the intermittent nature of the solar radiation. The key parameters discussed in this study are strong solution concentration, separator temperature which affects the hot fluid inlet temperature and turbine ammonia concentration. Solar parabolic collector system with vacuum tubes has been designed at the optimized power plant conditions. This work can be used in the selection of boiler, separator and turbine conditions to maximize the power output as well as efficiency of power generation system. The current model results a maximum limit temperature for separator as 150 °C at the Indian climatic conditions. A maximum specific power of 105 kW per kg/s of working fluid can be obtained at 80% of strong solution concentration with 140 °C separator temperature. The corresponding plant and cycle efficiencies are 5.25% and 13% respectively. But the maximum efficiencies of 6% and 15% can be obtained respectively for plant and Kalina cycle at 150 °C of separator temperature.

  13. Marginal thermal-neutron peak fluxes in systems with modulation of reactivity

    International Nuclear Information System (INIS)

    Alekseev, N.I.; Stolypin, V.S.

    1978-01-01

    A possibility of obtaining high (including marginal) thermal neutron peak fluxes PHIsub(m) in a light water trap of a pulsed fast reactor with modulation of reactivity has been studied. The dependences of sub(m) on the subcriticality and supercriticality as well as on the supercritical state duration have been calculated on stepped variations of the reactivity. The calculations show that PHIsub(m) of about 7.3x10 18 neutron/cm 2 xs with the effective pulse duration of approximately 150 μc, pulse frequency of approximately 1 Hz and at fuel temperature of approximately 1300 deg C can be obtained with the reactor. The comparative calculations show that sub(m) is 1.5 times higher than that of a booster obtained using a ''meson plant'' (designs of the booster and the reactor are equivalent). The neutron background between pulses in the reactor is much lower than in the booster, and there is no need for a power injector in the reactor altogether. Meanwhile the maximum attainable PHIsub(m) for the booster and the reactor are the same and equal approximately 2x10 19 neutron/cm 2 xs

  14. Thermal power plant operating regimes in future British power systems with increasing variable renewable penetration

    International Nuclear Information System (INIS)

    Edmunds, Ray; Davies, Lloyd; Deane, Paul; Pourkashanian, Mohamed

    2015-01-01

    Highlights: • This work investigates thermal power operating regimes in future power systems. • Gas plants have low utilisation in the scenarios considered. • Ramping intensity increases for gas plants and pumped storage. • Coal plants frequently operate at minimum stable levels and start-ups increase. • Grid emission intensity and total emission production remains substantial. - Abstract: This work investigates the operational requirements of thermal power plants in a number of potential future British power systems with increasing variable renewable penetration. The PLEXOS Integrated Energy Model has been used to develop the market models, with PLEXOS employing mixed integer programming to solve the unit commitment and economic dispatch problem, subject to a number of constraints. Initially, a model of the British power system was developed and validated. Subsequently, a 2020 test model was developed to analyse a number of future system structures with differing fuel and carbon prices and generation mixes. The study has found that in three of the four scenarios considered, the utilisation of gas power plants will be relatively low, but remains fundamental to the security of supply. Also, gas plants will be subject to more intense ramping. The findings have consequent implications for energy policy as expensive government interventions may be required to prevent early decommissioning of gas capacity, should the prevailing market conditions not guarantee revenue adequacy.

  15. Validation of CESAR Thermal-hydraulic Module of ASTEC V1.2 Code on BETHSY Experiments

    Science.gov (United States)

    Tregoures, Nicolas; Bandini, Giacomino; Foucher, Laurent; Fleurot, Joëlle; Meloni, Paride

    The ASTEC V1 system code is being jointly developed by the French Institut de Radioprotection et Sûreté Nucléaire (IRSN) and the German Gesellschaft für Anlagen und ReaktorSicherheit (GRS) to address severe accident sequences in a nuclear power plant. Thermal-hydraulics in primary and secondary system is addressed by the CESAR module. The aim of this paper is to present the validation of the CESAR module, from the ASTEC V1.2 version, on the basis of well instrumented and qualified integral experiments carried out in the BETHSY facility (CEA, France), which simulates a French 900 MWe PWR reactor. Three tests have been thoroughly investigated with CESAR: the loss of coolant 9.1b test (OECD ISP N° 27), the loss of feedwater 5.2e test, and the multiple steam generator tube rupture 4.3b test. In the present paper, the results of the code for the three analyzed tests are presented in comparison with the experimental data. The thermal-hydraulic behavior of the BETHSY facility during the transient phase is well reproduced by CESAR: the occurrence of major events and the time evolution of main thermal-hydraulic parameters of both primary and secondary circuits are well predicted.

  16. Thermal and Electrical Characterization of a Semi-Transparent Dye-Sensitized Photovoltaic Module under Real Operating Conditions

    Directory of Open Access Journals (Sweden)

    Cristina Cornaro

    2018-01-01

    Full Text Available Dye-sensitized solar cell technology is having an important role in renewable energy research due to its features and low-cost manufacturing processes. Devices based on this technology appear very well suited for integration into glazing systems due to their characteristics of transparency, color tuning and manufacturing directly on glass substrates. Field data of thermal and electrical characteristics of dye-sensitized solar modules (DSM are important since they can be used as input of building simulation models for the evaluation of their energy saving potential when integrated into buildings. However, still few studies in the literature provide this information. The study presented here aims to contribute to fill this lack providing a thermal and electrical characterization of a DSM in real operating conditions using a method developed in house. This method uses experimental data coming from test boxes exposed outdoor and dynamic simulation to provide thermal transmittance (U-value and solar heat gain coefficient (SHGC of a DSM prototype. The device exhibits a U-value of 3.6 W/m2·K, confirmed by an additional measurement carried on in the lab using a heat flux meter, and a SHGC of 0.2, value compliant with literature results. Electrical characterization shows an increase of module power with respect to temperature resulting DSM being suitable for integration in building facades.

  17. Development of user interface to support automatic program generation of nuclear power plant analysis by module-based simulation system

    International Nuclear Information System (INIS)

    Yoshikawa, Hidekazu; Mizutani, Naoki; Nakaya, Ken-ichiro; Wakabayashi, Jiro

    1988-01-01

    Module-based Simulation System (MSS) has been developed to realize a new software work environment enabling versatile dynamic simulation of a complex nuclear power system flexibly. The MSS makes full use of modern software technology to replace a large fraction of human software works in complex, large-scale program development by computer automation. Fundamental methods utilized in MSS and developmental study on human interface system SESS-1 to help users in generating integrated simulation programs automatically are summarized as follows: (1) To enhance usability and 'communality' of program resources, the basic mathematical models of common usage in nuclear power plant analysis are programed as 'modules' and stored in a module library. The information on usage of individual modules are stored in module database with easy registration, update and retrieval by the interactive management system. (2) Target simulation programs and the input/output files are automatically generated with simple block-wise languages by a precompiler system for module integration purpose. (3) Working time for program development and analysis in an example study of an LMFBR plant thermal-hydraulic transient analysis was demonstrated to be remarkably shortened, with the introduction of an interface system SESS-1 developed as an automatic program generation environment. (author)

  18. Emerging Changes in the Worldwide Power Sector: The Assets of Thermal Power

    Energy Technology Data Exchange (ETDEWEB)

    Moliere, Michel; Girardot, Amelie; Jones, Robert M.

    2007-07-01

    In forthcoming decades we will see major changes in the landscape of the worldwide power sector as CO2 management and incipient hydrocarbon scarcity exert their increasing influence. The power generation community must be prepared to satisfy a particularly complex and challenging set of requirements. These issues include curbing CO2 emissions, coping with surging primary energy prices, and compliance with regional and local emissions requirements such as SOx and NOx-while maintaining maximum efficiency. In this context, as confirmed by International Energy Agency forecasts, thermal power will maintain a prominent position in overall power generation since it enables the large capacity additions required in emerging countries. Thanks to their reliable assets (such as energy efficiency and environment) gas turbine-based power systems, including Gas Turbine Combined Cycles (GTCC) and Combined Heat & Power (CHP), will continue to be major contributors to worldwide power generation. However, evolving changes in the spectrum of fuels will create an additional challenge for power generation equipment manufacturers-requiring innovative technologies in fuel processing, combustion, and emission controls to address these needs. This paper reviews the factors underlining the changing power generation environment worldwide, including the increasing scarcity of conventional fuels and the growing interest in biofuels and hydrogen. Insights will be offered into various technologies needed to support the growing need for increased fuel flexibility.

  19. Output power analyses for the thermodynamic cycles of thermal power plants

    International Nuclear Information System (INIS)

    Sun Chen; Cheng Xue-Tao; Liang Xin-Gang

    2014-01-01

    Thermal power plant is one of the important thermodynamic devices, which is very common in all kinds of power generation systems. In this paper, we use a new concept, entransy loss, as well as exergy destruction, to analyze the single reheating Rankine cycle unit and the single stage steam extraction regenerative Rankine cycle unit in power plants. This is the first time that the concept of entransy loss is applied to the analysis of the power plant Rankine cycles with reheating and steam extraction regeneration. In order to obtain the maximum output power, the operating conditions under variant vapor mass flow rates are optimized numerically, as well as the combustion temperatures and the off-design flow rates of the flue gas. The relationship between the output power and the exergy destruction rate and that between the output power and the entransy loss rate are discussed. It is found that both the minimum exergy destruction rate and the maximum entransy loss rate lead to the maximum output power when the combustion temperature and heat capacity flow rate of the flue gas are prescribed. Unlike the minimum exergy destruction rate, the maximum entransy loss rate is related to the maximum output power when the highest temperature and heat capacity flow rate of the flue gas are not prescribed. (general)

  20. Complete Loss and Thermal Model of Power Semiconductors Including Device Rating Information

    DEFF Research Database (Denmark)

    Ma, Ke; Bahman, Amir Sajjad; Beczkowski, Szymon

    2015-01-01

    Thermal loading of power devices are closely related to the reliability performance of the whole converter system. The electrical loading and device rating are both important factors that determine the loss and thermal behaviors of power semiconductor devices. In the existing loss and thermal...

  1. New simultaneous thermogravimetry and modulated molecular beam mass spectrometry apparatus for quantitative thermal decomposition studies

    International Nuclear Information System (INIS)

    Behrens, R. Jr.

    1987-01-01

    A new type of instrument has been designed and constructed to measure quantitatively the gas phase species evolving during thermal decompositions. These measurements can be used for understanding the kinetics of thermal decomposition, determining the heats of formation and vaporization of high-temperature materials, and analyzing sample contaminants. The new design allows measurements to be made on the same time scale as the rates of the reactions being studied, provides a universal detection technique to study a wide range of compounds, gives quantitative measurements of decomposition products, and minimizes interference from the instrument on the measurements. The instrument design is based on a unique combination of thermogravimetric analysis (TGA), differential thermal analysis (DTA), and modulated beam mass spectroscopy (MBMS) which are brought together into a symbiotic relationship through the use of differentially pumped vacuum systems, modulated molecular beam techniques, and computer control and data-acquisition systems. A data analysis technique that calculates partial pressures in the reaction cell from the simultaneous microbalance force measurements and the modulated mass spectrometry measurements has been developed. This eliminates the need to know the ionization cross section, the ion dissociation channels, the quadrupole transmission, and the ion detector sensitivity for each thermal decomposition product prior to quantifying the mass spectral data. The operation of the instrument and the data analysis technique are illustrated with the thermal decomposition of contaminants from a precipitated palladium powder

  2. Certain aspects of the environmental impact of nuclear power engineering and thermal power engineering

    Energy Technology Data Exchange (ETDEWEB)

    Malenchenko, A F [AN Belorusskoj SSR, Minsk. Inst. Yadernoj Ehnergetiki

    1979-01-01

    A review is made of the both environmental impact and hazard to man resulting from nuclear power engineering as compared with those of thermal power engineering. At present, in addition to such criteria, as physical-chemical characteristic of energy sources, their efficiency and accessibility for exploitation, new requirements were substantiated in relation to safety of their utilization for environment. So, one of essential problems of nuclear power engineering development consists in assessment and prediction of radioecological consequence. The analysis and operating experience of more than 1000 reactor/years with no accidents and harm for pupulation show, that in respect to impact on environment and man nuclear power engineering is much more safe in comparison with energy sources using tradidional fossile fuel.

  3. Accident prevention ordinance 2.0 Thermal Power Plants

    International Nuclear Information System (INIS)

    Egyptien, H.H.; Fischermann, E.

    This accident prevention ordinance is to cover primarily the very section of a power station where fossil or nuclear energy is converted into thermal energy, e.g. by heating or vaporization of a heat source. In paragraph 1, 40 GJ/h are stipulated as the lower limit of capacity corresponding to about 11 MW. Therefore, the accident prevention ordinance does not only marshal the operation of steam generators in electricity supply utilities but also covers smaller industrial power stations which partly do only meet the company's own requirements. Pipes are only covered as far as they are operated in conjunction with a heat generator. The same applies to coal handling and ash removal facilities. This means that for heat release e.g. in the framework of a district heating grid, the transfer station to the distribution grid is regarded as being a border of the power station and thus a border to the area of application of the accident prevention ordinance. (orig./HP) [de

  4. Experimental thermal behavior of a power plant reheater

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, M. Manuela Prieto; Garcia, F. Javier Fernandez; Ramon, Ines Suarez [Departamento de Energia, Universidad de Oviedo, Campus de Viesques, 33204 Gijon, Asturias (Spain); Roces, Hilario Sanchez [Central Termica de Soto de Ribera, Soto de Ribera, Asturias (Spain)

    2006-04-15

    The process conditions of power plant components subjected to high pressures and temperatures are essential to determine their remaining life, availability and efficiency. It is, therefore, expedient to pay special attention to critical components, such as superheater and reheater heat exchangers, headers, and main and reheated steam lines. In this paper, on-line and off-line variables of a power plant reheater that has presented problems of thickness losses and repetitive tube fissures are studied. The fissures are associated with the effect of a thermal-mechanical mechanism. Off-line measurements were taken of the following variables: pressure, temperature, velocity and composition of the gases. On-line instrumentation was completed by the installation of specific thermocouples to ascertain the temperatures in the tubes outlet. Various angles for the fuel inlet of the burners and variations in the number and location of the working burners were also assayed. As a consequence of this analysis, it can be deduced that there are important differences in the outlet temperature of the reheater tubes that decrease for lower powers. Finally, it is pointed that a non-uniform distribution of the steam flow in the reheater might be the cause of the problem. (author)

  5. Fuel combustion in thermal power plants in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.

    1983-11-01

    The position of black coal in the energy balance of Japan is discussed. About 75% of electric energy is produced by thermal power plants. Eighty-five per cent of electricity is produced by power plants fired with liquid fuels and 3% by coal fired plants. Coal production in Japan, the forecast coal import to the country by 1990 (132 Mt/year), proportion of coal imported from various countries, chemical and physical properties of coal from Australia, China and Japan are discussed. Coal classification used in Japan is evaluated. The following topics associated with coal combustion in fossil-fuel power plants in Japan are discussed: coal grindability, types of pulverizing systems, slagging properties of boiler fuel in Japan, systems for slag removal, main types of steam boilers and coal fired furnaces, burner arrangement and design, air pollution control from fly ash, sulfur oxides and nitrogen oxides, utilization of fly ash for cement production, methods for removal of nitrogen oxides from flue gas using ammonia and catalysts or ammonia without catalysts, efficiency of nitrogen oxide control, abatement of nitrogen oxide emission from boilers by flue gas recirculation and reducing combustion temperatures. The results of research into air pollution control carried out by the Nagasaki Technical Institute are reviewed.

  6. Control of nitrogen oxides at thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Hall, R.E.

    1991-01-01

    Reviews reports presented at the International symposium on reduction of NO{sub x} emissions from stationary pollutant sources, held in San Francisco (USA) in March 1989. Topics concentrated on the latest trends in power engineering in the USA and Europe. Reports were dedicated to test results of pilot plant equipment employing the increasingly popular LNB, OFA, Reburn, SNCR, and SCR technologies. The following conclusions are drawn on the basis of the symposium proceedings: The nitric oxide problem may be considered exaggerated in regard to thermal power plants because of errors made during flue gas composition analysis. The combination of new combustion chambers and staged air input with simultaneous redesigning of equipment is most widely employed in the USA (achieving a 50% NO{sub x} reduction with minimum effect on power plant operation and maintenance costs). Economic sense demands that primary methods of NO{sub x} removal be used prior to SCR implementation. The SCR technology reducing NO{sub x} emission by 60-80% with ammonia to less than 5 ppm is the most popular flue gas denitrification method. 15 refs.

  7. Simulation and parametric optimisation of thermal power plant cycles

    Directory of Open Access Journals (Sweden)

    P. Ravindra Kumar

    2016-09-01

    Full Text Available The objective of the paper is to analyse parametric studies and optimum steam extraction pressures of three different (subcritical, supercritical and ultra-supercritical coal fired power plant cycles at a particular main steam temperature of 600 °C by keeping the reheat temperature at 537 °C and condenser pressure at 0.09 bar as constant. In order to maximize the heat rate gain possible with supercritical and ultra-supercritical steam conditions, eight stages of feed water heater arrangement with single reheater is considered. The system is optimized in such a way that the percentage exergetic losses are reduced for the increase of the exergetic efficiency and higher fuel utilization. The plant cycles are simulated and optimized by using Cycle Tempo 5.0 simulation software tool. From the simulation study, it is observed that the thermal efficiency of the three different power plant cycles obtained as 41.40, 42.48 and 43.03%, respectively. The specific coal consumption for three different power plant cycles are 0.56, 0.55 and 0.54 Tonnes/MWh. The improvement in feed water temperatures at the inlet of steam generator of respective cycles are 291, 305 and 316 °C.

  8. Assessment of inhalation risk due to radioactivity released from coal-based thermal power plant

    International Nuclear Information System (INIS)

    Sahu, S.K.; Pandit, G.G.; Shukla, V.K.; Puranik, V.D.; Kushwaha, H.S.

    2006-01-01

    In India, the coal based thermal power plants have been the major source of power generation in the past and would continue for decades to come. As the coal contains naturally occurring primordial radionuclides the burning of pulverized coal to produce energy for generation of electricity in thermal power plants will result in the emission of a variety of natural radioactive elements into the environment in the vicinity of thermal power plants. In this paper we have used two different methods for characterization of uncertainty in inhalation risk to the general public around 10 Kms radius in the neighborhood of a coal-fired thermal power plant. (author)

  9. A theoretical and experimental analysis of modulated laser fields and power spectra

    DEFF Research Database (Denmark)

    Olesen, Henning; Jacobsen, G.

    1982-01-01

    A general theoretical description of modulated laser fields and power spectra for a current modulated single-mode laser is derived, taking into account both the intensity and frequency modulation (IM and FM) of the emitted light. The theory relies on an explicit knowledge of the modulus as well...

  10. Star Power: Providing for the Gifted & Talented. Module 1. Characteristics of the Gifted/Talented.

    Science.gov (United States)

    Heinemann, Alison

    The document presents Module 1, characteristics of the gifted/talented student, of the Star Power modules, developed for school personnel who have an interest in or a need to explore the area of gifted and talented education. It is explained in an introductory section that the modules can be used for independent study, for small group interaction,…

  11. Star Power: Providing for the Gifted & Talented. Module 6. Underachievers Among the Gifted/Talented.

    Science.gov (United States)

    Heinemann, Alison

    The document presents Module 6, underachievers among the gifted/talented, of the Star Power modules developed for school personnel who have an interest in or a need to explore the area of gifted and talented education. It is explained in an introductory section that the modules can be used for independent study, for small group interaction, or for…

  12. Star Power: Providing for the Gifted & Talented. Module 9. Programs for the Gifted/Talented.

    Science.gov (United States)

    Mallis, Jackie; Heinemann, Alison

    The document presents Module 9, programs for the gifted/talented, of the Star Power modules developed for school personnel who have an interest in or a need to explore the area of gifted and talented education. It is explained in an introductory section that the modules can be used for independent study, for small group interaction, or for a large…

  13. Thermal Energy Corporation Combined Heat and Power Project

    Energy Technology Data Exchange (ETDEWEB)

    Turner, E. Bruce [Thermal Energy Corporation, Houston, TX (United States); Brown, Tim [Thermal Energy Corporation, Houston, TX (United States); Mardiat, Ed [Burns and McDonnell Engineering Company, Inc., Kansas City, MI (United States)

    2011-12-31

    To meet the planned heating and cooling load growth at the Texas Medical Center (TMC), Thermal Energy Corporation (TECO) implemented Phase 1 of a Master Plan to install an additional 32,000 tons of chilled water capacity, a 75,000 ton-hour (8.8 million gallon) Thermal Energy Storage (TES) tank, and a 48 MW Combined Heat and Power (CHP) system. The Department of Energy selected TMC for a $10 million grant award as part of the Financial Assistance Funding Opportunity Announcement, U.S. Department of Energy National Energy Technology, Recovery Act: Deployment of Combined Heat and Power (CHP) Systems, District Energy Systems, Waste Energy Recovery Systems, and Efficiency Industrial Equipment Funding Opportunity Number: DE-FOA-0000044 to support the installation of a new 48 MW CHP system at the TMC located just outside downtown Houston. As the largest medical center in the world, TMC is home to many of the nation's best hospitals, physicians, researchers, educational institutions, and health care providers. TMC provides care to approximately six million patients each year, and medical instruction to over 71,000 students. A medical center the size of TMC has enormous electricity and thermal energy demands to help it carry out its mission. Reliable, high-quality steam and chilled water are of utmost importance to the operations of its many facilities. For example, advanced medical equipment, laboratories, laundry facilities, space heating and cooling all rely on the generation of heat and power. As result of this project TECO provides this mission critical heating and cooling to TMC utilizing a system that is both energy-efficient and reliable since it provides the capability to run on power independent of the already strained regional electric grid. This allows the medical center to focus on its primary mission providing top quality medical care and instruction without worrying about excessive energy costs or the loss of heating and cooling due to the risk of power

  14. A real time measurement of junction temperature variation in high power IGBT modules for wind power converter application

    DEFF Research Database (Denmark)

    Ghimire, Pramod; Pedersen, Kristian Bonderup; de Vega, Angel Ruiz

    2014-01-01

    This paper presents a real time measurement of on-state forward voltage and estimating the junction temperature for a high power IGBT module during a power converter operation. The power converter is realized as it can be used for a wind turbine system. The peak of the junction temperature is dec...

  15. Power cycling test and failure analysis of molded Intelligent Power IGBT Module under different temperature swing durations

    DEFF Research Database (Denmark)

    Choi, Uimin; Blaabjerg, Frede; Jørgensen, Søren

    2016-01-01

    on the lifetime of 600 V, 30 A, 3-phase molded Intelligent PowerModules (IPM) and their failuremechanismsare investigated. The study is based on the accelerated power cycling test results of 36 samples under 6 different conditions and tests are performed under realistic electrical conditions by an advanced power...

  16. Thermal wave interference with high-power VCSEL arrays for locating vertically oriented subsurface defects

    Science.gov (United States)

    Thiel, Erik; Kreutzbruck, Marc; Studemund, Taarna; Ziegler, Mathias

    2018-04-01

    Among the photothermal methods, full-field thermal imaging is used to characterize materials, to determine thicknesses of layers, or to find inhomogeneities such as voids or cracks. The use of classical light sources such as flash lamps (impulse heating) or halogen lamps (modulated heating) led to a variety of nondestructive testing methods, in particular, lock-in and flash-thermography. In vertical-cavity surface-emitting lasers (VCSELs), laser light is emitted perpendicularly to the surface with a symmetrical beam profile. Due to the vertical structure, they can be arranged in large arrays of many thousands of individual lasers, which allows power scaling into the kilowatt range. Recently, a high-power yet very compact version of such a VCSEL-array became available that offers both the fast timing behavior of a laser as well as the large illumination area of a lamp. Moreover, it allows a spatial and temporal control of the heating because individual parts of the array can be controlled arbitrarily in frequency, amplitude, and phase. In conjunction with a fast infrared camera, such structured heating opens up a field of novel thermal imaging and testing methods. As a first demonstration of this approach, we chose a testing problem very challenging to conventional thermal infrared testing: The detection of very thin subsurface defects perpendicularly oriented to the surface of metallic samples. First, we generate destructively interfering thermal wave fields, which are then affected by the presence of defects within their reach. It turned out that this technique allows highly sensitive detection of subsurface defects down to depths in excess of the usual thermographic rule of thumb, with no need for a reference or surface preparation.

  17. Recommendations for the market introduction of solar thermal power stations

    International Nuclear Information System (INIS)

    Trieb, F.; Nitsch, J.

    1998-01-01

    Until 2010, solar thermal power stations based on parabolic trough concentrating collectors can become a competitive option on the world's electricity market, if the market extension of this mature technology is supported by a concerted, long-term programme capable of bundling the forces of industry, finance, insurance and politics. Technical improvements based on the experience of over ten years of successful operation, series production and economies of scale will lead to a further cost reduction of 50% and to electricity costs of 0.06 - 0.04 US$/kWh for hybrid steam cycles and hybrid combined cycles, respectively. Until 2010, a capacity of 7 GW will be installed, avoiding 16 million tons of carbon dioxide per year. The programme comprises an investment of 16 billion US$ and requires external funding of 6%. (author)

  18. Benthos of a coastal power station thermal discharge canal

    Energy Technology Data Exchange (ETDEWEB)

    Bamber, R.N.; Spencer, J.F.

    1984-08-01

    Kingsnorth Power Station, on the river Medway Estuary, Kent, discharges cooling water into a canal comprising a 4 km creek system. A comprehensive investigation of the sublittoral benthic fauna of the discharge system was undertaken from January 1979 to September 1981. The macrofauna is significantly suppressed at sites along the discharge canal, representing a community with half the number of species comprising dense populations of a few dominant opportunistic species tolerant of thermal stress (e.g. Tubificoides, Cauleriella) and not those characteristic of organic pollution stress communities. The latter are regular summer immigrants in the creek, but persist only in low numbers if at all in the winter (e.g. Polydora ciliata). This suppression is the result of an approximately 10/sup 0/C temperature front between the heated discharge water and ambient estuarine water, passing over the sea bed with the ebbing and flooding tide four times each day. 39 references, 11 figures, 3 tables.

  19. Thermal energy storage for the Stirling engine powered automobile

    Science.gov (United States)

    Morgan, D. T. (Editor)

    1979-01-01

    A thermal energy storage (TES) system developed for use with the Stirling engine as an automotive power system has gravimetric and volumetric storage densities which are competitive with electric battery storage systems, meets all operational requirements for a practical vehicle, and can be packaged in compact sized automobiles with minimum impact on passenger and freight volume. The TES/Stirling system is the only storage approach for direct use of combustion heat from fuel sources not suitable for direct transport and use on the vehicle. The particular concept described is also useful for a dual mode TES/liquid fuel system in which the TES (recharged from an external energy source) is used for short duration trips (approximately 10 miles or less) and liquid fuel carried on board the vehicle used for long duration trips. The dual mode approach offers the potential of 50 percent savings in the consumption of premium liquid fuels for automotive propulsion in the United States.

  20. Chemistry of the water in thermal power plants

    International Nuclear Information System (INIS)

    Freier, R.K.

    1984-01-01

    This textbook and practical manual gives a comprehensive review of the scientific knowledge of water as operating substance and of the chemistry of water in thermal power plants. The fundamentals of water chemistry and of the conventional and nuclear water/steam circuit are described. The contents of the chapters are: 1. The atom, 2. The chemical bond, 3. The dissolving capacity of water, 4. Operational parameters and their measurement, 5. Corrosion, 6. The water/steam coolant loop of conventional plants (WSC), 7. The pressurized water reactor (PWR), 8. The boiling water reactor (BWR), 9. The total and partial desalination properties of ion exchangers, 10. The cooling water, 11. The failure of Harrisburg in a simple presentation. (HK) [de

  1. Thermal design and analysis of high power star sensors

    Directory of Open Access Journals (Sweden)

    Fan Jiang

    2015-09-01

    Full Text Available The requirement for the temperature stability is very high in the star sensors as the high precision needs for the altitude information. Thermal design and analysis thus is important for the high power star sensors and their supporters. CCD, normally with Peltier thermoelectric cooler (PTC, is the most important sensor component in the star sensors, which is also the main heat source in the star sensors suite. The major objective for the thermal design in this paper is to design a radiator to optimize the heat diffusion for CCD and PTC. The structural configuration of star sensors, the heat sources and orbit parameters were firstly introduced in this paper. The influences of the geometrical parameters and coating material characteristics of radiators on the heat diffusion were investigated by heat flux analysis. Carbon–carbon composites were then chosen to improve the thermal conductivity for the sensor supporters by studying the heat transfer path. The design is validated by simulation analysis and experiments on orbit. The satellite data show that the temperatures of three star sensors are from 17.8 °C to 19.6 °C, while the simulation results are from 18.1 °C to 20.1 °C. The temperatures of radiator are from 16.1 °C to 16.8 °C and the corresponding simulation results are from 16.0 °C to 16.5 °C. The temperature variety of each star sensor is less than 2 °C, which satisfies the design objectives.

  2. Theoretical study on thermal stability of molten salt for solar thermal power

    International Nuclear Information System (INIS)

    Wei, Xiaolan; Peng, Qiang; Ding, Jing; Yang, Xiaoxi; Yang, Jianping; Long, Bin

    2013-01-01

    Molten salt (HTS) composed of 53% KNO 3 , 40% NaNO 2 and 7 wt.% NaNO 3 has been used as heat transfer media and thermal storage fluid in the solar thermal power, but thermal decomposition will occur at higher temperature because of the oxidation of nitrite to nitrate in the air. In this paper, the reaction mechanism of NO 2 − oxidation is researched by quantum mechanical method. The results show that two components of the transition state (O 2 NO 2 − ) and intermediate ([NO 4 − ]) are found in the reaction. This reaction is an exothermic reaction and the activation barrier is 94.0 kJ mol −1 . The energy difference of this reaction is very large, so the reaction rate is very slow. -- Highlights: ► The mechanism of the oxidation of nitrite salt in HTS is explained. ► Two components of the transition state (O 2 NO 2 − ) and intermediate ([NO 4 − ]) are found. ► The activation barrier of the nitrite oxidation is determined

  3. Parameter Estimation of the Thermal Network Model of a Machine Tool Spindle by Self-made Bluetooth Temperature Sensor Module

    Directory of Open Access Journals (Sweden)

    Yuan-Chieh Lo

    2018-02-01

    Full Text Available Thermal characteristic analysis is essential for machine tool spindles because sudden failures may occur due to unexpected thermal issue. This article presents a lumped-parameter Thermal Network Model (TNM and its parameter estimation scheme, including hardware and software, in order to characterize both the steady-state and transient thermal behavior of machine tool spindles. For the hardware, the authors develop a Bluetooth Temperature Sensor Module (BTSM which accompanying with three types of temperature-sensing probes (magnetic, screw, and probe. Its specification, through experimental test, achieves to the precision ±(0.1 + 0.0029|t| °C, resolution 0.00489 °C, power consumption 7 mW, and size Ø40 mm × 27 mm. For the software, the heat transfer characteristics of the machine tool spindle correlative to rotating speed are derived based on the theory of heat transfer and empirical formula. The predictive TNM of spindles was developed by grey-box estimation and experimental results. Even under such complicated operating conditions as various speeds and different initial conditions, the experiments validate that the present modeling methodology provides a robust and reliable tool for the temperature prediction with normalized mean square error of 99.5% agreement, and the present approach is transferable to the other spindles with a similar structure. For realizing the edge computing in smart manufacturing, a reduced-order TNM is constructed by Model Order Reduction (MOR technique and implemented into the real-time embedded system.

  4. Realisation of serial powering of ATLAS pixel modules

    CERN Document Server

    Stockmanns, Tobias; Fischer, P; Hügging, Fabian Georg; Peric, Ivan; Runólfsson, Ogmundur; Wermes, Norbert

    2004-01-01

    Modern hybrid pixel detectors as they will be used for the next generation of high energy collider experiments like LHC avail deep sub micron technology for the readout electronics. To operate chips in this technology low supply voltages of 2.0 V to 2.5 V and high currents to achieve the desired performance are needed. Due to the long and low mass supply cables this high current leads to a significant voltage drop so that voltage fluctuations at the chip result, when the supply current changes. Therefore the parallel connection of the readout electronics with the power supplies imposes severe constraints on a detector with respect to voltage fluctuations and cable mass. To bypass this problem a new concept of serially connecting modules in a supply chain was developed. The basic idea of the concept, the potential risk and ways to minimize these risks are presented. In addition, studies of the implementation of this technology as an alternative for a possible upgrade of the ATLAS pixel detector are shown. In p...

  5. Hybrid Solar: A Review on Photovoltaic and Thermal Power Integration

    Directory of Open Access Journals (Sweden)

    T. T. Chow

    2012-01-01

    Full Text Available The market of solar thermal and photovoltaic electricity generation is growing rapidly. New ideas on hybrid solar technology evolve for a wide range of applications, such as in buildings, processing plants, and agriculture. In the building sector in particular, the limited building space for the accommodation of solar devices has driven a demand on the use of hybrid solar technology for the multigeneration of active power and/or passive solar devices. The importance is escalating with the worldwide trend on the development of low-carbon/zero-energy buildings. Hybrid photovoltaic/thermal (PVT collector systems had been studied theoretically, numerically, and experimentally in depth in the past decades. Together with alternative means, a range of innovative products and systems has been put forward. The final success of the integrative technologies relies on the coexistence of robust product design/construction and reliable system operation/maintenance in the long run to satisfy the user needs. This paper gives a broad review on the published academic works, with an emphasis placed on the research and development activities in the last decade.

  6. Revitalization of Tuzla Thermal Power Plant's Unit 3 (100 MW)

    International Nuclear Information System (INIS)

    Sakovic, A.; Praso, N.

    1998-01-01

    Power Plant Revitalization is a highly ranged concept essentially aimed at continued operations of the generating unit at, or near, rated capacities for the rest of the economic life of the plant or even for an extended life. In essence, the need to rehabilitate may arise due to reasons such as low availability factor, low efficiency, increasing operating and maintenance costs, loss of reliability, drop in safety of plant and personnel, poor maintainability or environmental requirements. The term revitalization is therefore normally used in the context to cover the range of activities including repairing components, replacing equipment, modifying systems, adding new system and equipment and perhaps restoration to rated capacities. This exercise on already complex power generation process will naturally require the application of various technologies in order to ensure a safe and efficient installation of electricity supply. In normal conditions of producing and consumption of electricity (load demands) in order to answer the question of what kind of revitalization to undertake it is necessary to state at the very beginning: - whether it is necessary, from the point of equipment wear-out, to revitalize all equipment at once (one-phase revitalization), or - whether it is possible to postpone the revitalization of a part of equipment for the next period (phased revitalization). Both concepts have some specific advantages and disadvantages. In essence the decision-making process between these two approaches, three basic conditions should be considered: technical-technological adequacy, energy-economy adequacy and financial adequacy. This paper covers general considerations, approach and methodology implemented during the revitalization the Tuzla Thermal Power Plant's Unit 3 (100MW) which was imposed by urgent demands of the Power System, the war conditions and financial possibilities including: - General data on TPP Tuzla and Unit 3 - Scope of work and economic effects

  7. Dark Energy Constraints from the Thermal Sunyaev Zeldovich Power Spectrum

    Science.gov (United States)

    Bolliet, Boris; Comis, Barbara; Komatsu, Eiichiro; Macías-Pérez, Juan Francisco

    2018-03-01

    We constrain the dark energy equation of state parameter, w, using the power spectrum of the thermal Sunyaev-Zeldovich (tSZ) effect. We improve upon previous analyses by taking into account the trispectrum in the covariance matrix and marginalising over the foreground parameters, the correlated noise, the mass bias B in the Planck universal pressure profile, and all the relevant cosmological parameters (i.e., not just Ωm and σ8). We find that the amplitude of the tSZ power spectrum at ℓ ≲ 103 depends primarily on F ≡ σ8(Ωm/B)0.40h-0.21, where B is related to more commonly used variable b by B = (1 - b)-1. We measure this parameter with 2.6% precision, F = 0.460 ± 0.012 (68% CL). By fixing the bias to B = 1.25 and adding the local determination of the Hubble constant H0 and the amplitude of the primordial power spectrum constrained by the Planck Cosmic Microwave Background (CMB) data, we find w = -1.10 ± 0.12, σ8 = 0.802 ± 0.037, and Ωm = 0.265 ± 0.022 (68% CL). Our limit on w is consistent with and is as tight as that from the distance-alone constraint from the CMB and H0. Finally, by combining the tSZ power spectrum and the CMB data we find, in the Λ Cold Dark Matter (CDM) model, the mass bias of B = 1.71 ± 0.17, i.e., 1 - b = 0.58 ± 0.06 (68% CL).

  8. Efficiency Study of a Commercial Thermoelectric Power Generator (TEG) Under Thermal Cycling

    Science.gov (United States)

    Hatzikraniotis, E.; Zorbas, K. T.; Samaras, I.; Kyratsi, Th.; Paraskevopoulos, K. M.

    2010-09-01

    Thermoelectric generators (TEGs) make use of the Seebeck effect in semiconductors for the direct conversion of heat to electrical energy. The possible use of a device consisting of numerous TEG modules for waste heat recovery from an internal combustion (IC) engine could considerably help worldwide efforts towards energy saving. However, commercially available TEGs operate at temperatures much lower than the actual operating temperature range in the exhaust pipe of an automobile, which could cause structural failure of the thermoelectric elements. Furthermore, continuous thermal cycling could lead to reduced efficiency and lifetime of the TEG. In this work we investigate the long-term performance and stability of a commercially available TEG under temperature and power cycling. The module was subjected to sequential hot-side heating (at 200°C) and cooling for long times (3000 h) in order to measure changes in the TEG’s performance. A reduction in Seebeck coefficient and an increase in resistivity were observed. Alternating-current (AC) impedance measurements and scanning electron microscope (SEM) observations were performed on the module, and results are presented and discussed.

  9. Implementation of CFD module in the KORSAR thermal-hydraulic system code

    Energy Technology Data Exchange (ETDEWEB)

    Yudov, Yury V.; Danilov, Ilia G.; Chepilko, Stepan S. [Alexandrov Research Inst. of Technology (NITI), Sosnovy Bor (Russian Federation)

    2015-09-15

    The Russian KORSAR/GP (hereinafter KORSAR) computer code was developed by a joint team from Alexandrov NITI and OKB ''Gidropress'' for VVER safety analysis and certified by the Rostechnadzor of Russia in 2009. The code functionality is based on a 1D two-fluid model for calculation of two-phase flows. A 3D CFD module in the KORSAR computer code is being developed by Alexandrov NITI for representing 3D effects in the downcomer and lower plenum during asymmetrical loop operation. The CFD module uses Cartesian grid method with cut cell approach. The paper presents a numerical algorithm for coupling 1D and 3D thermal- hydraulic modules in the KORSAR code. The combined pressure field is calculated by the multigrid method. The performance efficiency of the algorithm for coupling 1D and 3D modules was demonstrated by solving the benchmark problem of mixing cold and hot flows in a T-junction.

  10. Chemical and thermal modulation of molecular motor activities

    Science.gov (United States)

    Hong, Weili

    Molecular motors of kinesin and dynein families are responsible for various intracellular activities, from long distance movement of organelles, vesicles, protein complexes, and mRNAs to powering mitotic processes. They can take nanometer steps using chemical energy from the hydrolysis of ATP (adenosine triphosphate), and their dysfunction is involved in many neurodegenerative diseases that require long distance transport of cargos. Here I report on the study of the properties of molecular motors at a single-molecule level using optical trappings. I first studied the inhibition properties of kinesin motors by marine natural compound adociasulfates. I showed that adociasulfates compete with microtubules for binding to kinesins and thus inhibit kinesins' activity. Although adociasulfates are a strong inhibitor for all kinesin members, they show a much higher inhibition effect for conventional kinesins than for mitotic kinesins. Thus adociasulfates can be used to specifically inhibit conventional kinesins. By comparing the inhibition of kinesins by two structurally similar adociasulfates, one can see that the negatively charged sulfate residue of adociasulfates can be replaced by other negative residues and thus make it possible for adociasulfate-derived compounds to be more cell permeable. Kinesins and dyneins move cargos towards opposite directions along a microtubule. Cargos with both kinesins and dyneins attached often move bidirectionally due to undergoing a tug-of-war between the oppositely moving kinesin and dynein motors. Here I studied the effect of temperature on microtubule-based kinesin and dynein motor transport. While kinesins' and dyneins' velocities are closely matched above 15 °C, below this temperature the dyneins' velocity decreases much faster than the kinesins'. The kinesins' and dyneins' forces do not measurably change with temperature. The results suggest that temperature has significant effects on bidirectional transport and can be used to

  11. Valves for condenser-cooling-water circulating piping in thermal power station and nuclear power station

    International Nuclear Information System (INIS)

    Kondo, Sumio

    1977-01-01

    Sea water is mostly used as condenser cooling water in thermal and nuclear power stations in Japan. The quantity of cooling water is 6 to 7 t/sec per 100,000 kW output in nuclear power stations, and 3 to 4 t/sec in thermal power stations. The pipe diameter is 900 to 2,700 mm for the power output of 75,000 to 1,100,000 kW. The valves used are mostly butterfly valves, and the reliability, economy and maintainability must be examined sufficiently because of their important role. The construction, number and arrangement of the valves around a condenser are different according to the types of a turbine and the condenser and reverse flow washing method. Three types are illustrated. The valves for sea water are subjected to the electrochemical corrosion due to sea water, the local corrosion due to stagnant water, the fouling by marine organisms, the cavitation due to valve operation, and the erosion by earth and sand. The fundamental construction, use and features of butterfly valves are described. The cases of the failure and repair of the valves after their delivery are shown, and they are the corrosion of valve bodies and valve seats, and the separation of coating and lining. The newly developed butterfly valve with overall water-tight rubber lining is introduced. (Kako, I.)

  12. Summary assessment of solar thermal parabolic dish technology for electrical power generation

    Science.gov (United States)

    Penda, P. L.; Fujita, T.; Lucas, J. W.

    1985-01-01

    An assessment is provided of solar thermal parabolic dish technology for electrical power generation. The assessment is based on the development program undertaken by the Jet Propulsion Laboratory for the U.S. Department of Energy and covers the period from the initiation of the program in 1976 through mid-1984. The program was founded on developing components and subsystems that are integrated into parabolic dish power modules for test and evaluation. The status of the project is summarized in terms of results obtained through testing of modules, and the implications of these findings are assessed in terms of techno-economic projections and market potential. The techno-economic projections are based on continuation of an evolutionary technological development program and are related to the accomplishments of the program as of mid-1984. The accomplishments of the development effort are summarized for each major subsystem including concentrators, receivers, and engines. The ramifications of these accomplishments are assessed in the context of developmental objectives and strategies.

  13. A Comprehensive Investigation on the Short Circuit Performance of MW-level IGBT Power Modules

    DEFF Research Database (Denmark)

    Wu, Rui; Reigosa, Paula Diaz; Iannuzzo, Francesco

    2015-01-01

    This paper investigates the short circuit performance of commercial 1.7 kV / 1 kA IGBT power modules by means of a 6 kA Non-Destructive-Tester. A mismatched current distribution among the parallel chips has been observed, which can reduce the short circuit capability of the IGBT power module unde...... short circuit conditions. Further Spice simulations reveal that the stray parameters inside the module play an important role in contributing to such a phenomenon....

  14. Mathematical model for solar drying of potato cylinders with thermal conductivity radially modulated

    Science.gov (United States)

    Trujillo Arredondo, Mariana

    2014-05-01

    A mathematical model for drying potato cylinders using solar radiation is proposed and solved analytically. The model incorporates the energy balance for the heat capacity of the potato, the radiation heat transfer from the potato toward the drying chamber and the solar radiation absorbed by the potato during the drying process. Potato cylinders are assumed to exhibit a thermal conductivity which is radially modulated. The method of the Laplace transform, with integral Bromwich and residue theorem will be applied and the analytic solutions for the temperature profiles in the potato cylinder will be derived in the form of an infinite series of Bessel functions, when the thermal conductivity is constant; and in the form of an infinite series of Heun functions, when the thermal conductivity has a linear radial modulation. All computations are performed using computer algebra, specifically Maple. It is expected that the analytical results obtained will be useful in food engineering and industry. Our results suggest some lines for future investigations such as the adoption of more general forms of radial modulation for the thermal conductivity of potato cylinders; and possible applications of other computer algebra software such as Maxima and Mathematica.

  15. A Method for testing the integrated thermal resistance of thermoelectric modules

    Science.gov (United States)

    Gao, Junling; Du, Qungui; Chen, Min

    2013-11-01

    The integrated thermal resistance (ITR) of thermoelectric modules (TEMs) is an important parameter that represents the thermal-conduction of ceramic substrates, copper conducting strips, and welding material used in the TEM as well as the thermal contact resistances between different materials. In this study, an accurate and practical test method is proposed for the ITR of TEMs according to thermoelectric heat transfer theory and the equivalent characteristics of heat flux through the cold and hot sides of TEMs in an open-circuit situation. By using such measurements and comparisons, it is verified that the measured ITR value in our mode is accurate and reliable. In particular this method accurately predicts the actual operating conditions of TEMs, in which TEMs are under certain mechanical pressure. It effectively solves the problem of thermal resistance extraction from operating TEMs and is of great significance in their analysis and optimization.

  16. Unexpected low thermal conductivity and large power factor in Dirac semimetal Cd3As2

    Science.gov (United States)

    Cheng, Zhang; Tong, Zhou; Sihang, Liang; Junzhi, Cao; Xiang, Yuan; Yanwen, Liu; Yao, Shen; Qisi, Wang; Jun, Zhao; Zhongqin, Yang; Faxian, Xiu

    2016-01-01

    Thermoelectrics has long been considered as a promising way of power generation for the next decades. So far, extensive efforts have been devoted to the search of ideal thermoelectric materials, which require both high electrical conductivity and low thermal conductivity. Recently, the emerging Dirac semimetal Cd3As2, a three-dimensional analogue of graphene, has been reported to host ultra-high mobility and good electrical conductivity as metals. Here, we report the observation of unexpected low thermal conductivity in Cd3As2, one order of magnitude lower than the conventional metals or semimetals with a similar electrical conductivity, despite the semimetal band structure and high electron mobility. The power factor also reaches a large value of 1.58 mW·m-1·K-2 at room temperature and remains non-saturated up to 400 K. Corroborating with the first-principles calculations, we find that the thermoelectric performance can be well-modulated by the carrier concentration in a wide range. This work demonstrates the Dirac semimetal Cd3As2 as a potential candidate of thermoelectric materials. Project supported by the National Young 1000 Talent Plan China, the Pujiang Talent Plan in Shanghai, China, the National Natural Science Foundation of China (Grant Nos. 61322407 and 11474058), the Fund for Fostering Talents in Basic Science of the National Natural Science Foundation of China (Grant No. J1103204), and the National Basic Research Program of China (Grant No. 2011CB921803).

  17. Direct Estimation of Power Distribution in Reactors for Nuclear Thermal Space Propulsion

    Science.gov (United States)

    Aldemir, Tunc; Miller, Don W.; Burghelea, Andrei

    2004-02-01

    A recently proposed constant temperature power sensor (CTPS) has the capability to directly measure the local power deposition rate in nuclear reactor cores proposed for space thermal propulsion. Such a capability reduces the uncertainties in the estimated power peaking factors and hence increases the reliability of the nuclear engine. The CTPS operation is sensitive to the changes in the local thermal conditions. A procedure is described for the automatic on-line calibration of the sensor through estimation of changes in thermal .conditions.

  18. Ocean thermal energy conversion power system development-I. Phase I. Preliminary design report. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-18

    The results of a conceptual and preliminary design study of Ocean Thermal Energy Conversion (OTEC) closed loop ammonia power system modules performed by Lockheed Missiles and Space Company, Inc. (LMSC) are presented. This design study is the second of 3 tasks in Phase I of the Power System Development-I Project. The Task 2 objectives were to develop: 1) conceptual designs for a 40 to 50-MW(e) closed cycle ammonia commercial plant size power module whose heat exchangers are immersed in seawater and whose ancillary equipments are in a shirt sleeve environment; preliminary designs for a modular application power system sized at 10-MW(e) whose design, construction and material selection is analogous to the 50 MW(e) module, except that titanium tubes are to be used in the heat exchangers; and 3) preliminary designs for heat exchanger test articles (evaporator and condenser) representative of the 50-MW(e) heat exchangers using aluminum alloy, suitable for seawater service, for testing on OTEC-1. The reference ocean platform was specified by DOE as a surface vessel with the heat exchanger immersed in seawater to a design depth of 0 to 20 ft measured from the top of the heat exchanger. For the 50-MW(e) module, the OTEC 400-MW(e) Plant Ship, defined in the Platform Configuration and Integration study, was used as the reference platform. System design, performance, and cost are presented. (WHK)

  19. Thermal performance monitoring and assessment in Dukovany nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Madron, F. [Chemplant Technology s.r.o., Hrncirska 4, 400 01 Usti nad Labem (Czech Republic); Papuga, J. [CEZ a.s., JE Dukovany, 675 50 Dukovany (Czech Republic); Pliska, J. [I and C ENERGO a.s., Prazska 684, 674 01 Trebic (Czech Republic)

    2006-07-01

    Competition in the European electricity market forces generators to achieve - in compliance with safety and environmental standards - efficiency of production as high as possible. This efficiency or heat rate is an important indicator of both the condition of the plant equipment and the quality of plant operation. Similar thermal performance indicators can also be calculated for components of the plant equipment such as heat exchangers. However, it is not easy to quantify these indicators with sufficient precision so that the results can be used for conduct of plant operation in near-real time and for predictive maintenance. This paper describes a present state of the system monitoring and evaluating thermal performance of the reactor units in Dukovany Nuclear Power Plant. The system provides information on actual and desirable (should-be) values of thermal performance indicators for control room operators, performance engineers and maintenance planners. The system is designed to monitor steady states and has two main functions: data validation and process simulation. Data validation is based on data reconciliation methodology and carried out with Recon software by Chemplant Technology. A detailed model of the secondary side for mass and heat balancing has been made up by means of the Recon's graphical editor; now it contains roughly 300 flows and employs data of about 200 measurements. Main advantages of the data reconciliation are: - reconciled data are consistent with the model, - reconciled data are more precise than data directly measured with consequence that the thermal power of steam generators is determined with substantially lower uncertainty than before - data reconciliation represents a solid basis for detection and identification of data corrupted by gross errors. Simulation is performed with a different analytical model of plant components configured into secondary side. The model has been developed by I and C Energo. Main purposes of simulation

  20. Taiwan Power Company's power distribution analysis and fuel thermal margin verification methods for pressurized water reactors

    International Nuclear Information System (INIS)

    Huang, P.H.

    1995-01-01

    Taiwan Power Company's (TPC's) power distribution analysis and fuel thermal margin verification methods for pressurized water reactors (PWRs) are examined. The TPC and the Institute of Nuclear Energy Research started a joint 5-yr project in 1989 to establish independent capabilities to perform reload design and transient analysis utilizing state-of-the-art computer programs. As part of the effort, these methods were developed to allow TPC to independently perform verifications of the local power density and departure from nucleate boiling design bases, which are required by the reload safety evaluation for the Maanshan PWR plant. The computer codes utilized were extensively validated for the intended applications. Sample calculations were performed for up to six reload cycles of the Maanshan plant, and the results were found to be quite consistent with the vendor's calculational results

  1. Hybrid intelligent monironing systems for thermal power plant trips

    Science.gov (United States)

    Barsoum, Nader; Ismail, Firas Basim

    2012-11-01

    Steam boiler is one of the main equipment in thermal power plants. If the steam boiler trips it may lead to entire shutdown of the plant, which is economically burdensome. Early boiler trips monitoring is crucial to maintain normal and safe operational conditions. In the present work two artificial intelligent monitoring systems specialized in boiler trips have been proposed and coded within the MATLAB environment. The training and validation of the two systems has been performed using real operational data captured from the plant control system of selected power plant. An integrated plant data preparation framework for seven boiler trips with related operational variables has been proposed for IMSs data analysis. The first IMS represents the use of pure Artificial Neural Network system for boiler trip detection. All seven boiler trips under consideration have been detected by IMSs before or at the same time of the plant control system. The second IMS represents the use of Genetic Algorithms and Artificial Neural Networks as a hybrid intelligent system. A slightly lower root mean square error was observed in the second system which reveals that the hybrid intelligent system performed better than the pure neural network system. Also, the optimal selection of the most influencing variables performed successfully by the hybrid intelligent system.

  2. Feasibility study on modernization of North Bangkok Thermal Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    With an objective to save energies and reduce global warming gas emission, a feasibility study was performed on the oil burning thermal power plant in the city of North Bangkok in Thailand to reconstruct the plant into a natural gas burning combined cycle power plant. In the project, the old facilities with an output of 237.8 MW using three steam turbines in total will be reconstructed into a plant comprising of two steam turbines for 256,2 MW and two gas turbines for 460.4 MW, or a facility of 716.6 MW in total. The plant construction will have the gas turbines, steam turbines, generators, and a waste heat recovered steam generator fixed on one axis, two of which will be installed. The gas turbines will use natural gas as fuel, and the steam turbines will be operated by steam from the waste heat recovered steam generator. As a result of the discussions, the reduction of the energy consumption for a period of 40 years will correspond to crude oil of 20,560 kt, while the reduction of the global warming gas emission will be 107,200 t-CO2. In addition, the energy saving cost will be 9-ton crude oil equivalent/one million yen, and the cost for reduction of the global warming gas emission will be 47 t-CO2/one million yen. (NEDO)

  3. Exergy Analysis of Operating Lignite Fired Thermal Power Plant

    Directory of Open Access Journals (Sweden)

    K. Murugesan

    2009-01-01

    Full Text Available The energy assessment must be made through the energy quantity as well as the quality. But the usual energy analysisevaluates the energy generally on its quantity only. However, the exergy analysis assesses the energy on quantity as well asthe quality. The aim of the exergy analysis is to identify the magnitudes and the locations of real energy losses, in order toimprove the existing systems, processes or components. The present paper deals with an exergy analysis performed on anoperating 50MWe unit of lignite fired steam power plant at Thermal Power Station-I, Neyveli Lignite Corporation Limited,Neyveli, Tamil Nadu, India. The exergy losses occurred in the various subsystems of the plant and their components havebeen calculated using the mass, energy and exergy balance equations. The distribution of the exergy losses in several plantcomponents during the real time plant running conditions has been assessed to locate the process irreversibility. The Firstlaw efficiency (energy efficiency and the Second law efficiency (exergy efficiency of the plant have also been calculated.The comparison between the energy losses and the exergy losses of the individual components of the plant shows that themaximum energy losses of 39% occur in the condenser, whereas the maximum exergy losses of 42.73% occur in the combustor.The real losses of energy which has a scope for the improvement are given as maximum exergy losses that occurredin the combustor.

  4. Thermal pollution of rivers and reservoirs by discharges of heated water from thermal and nuclear power plants

    International Nuclear Information System (INIS)

    Makarov, I.

    1974-12-01

    The problems are discussed of the thermal pollution of rivers and water reservoirs by discharges of heated water from thermal and nuclear power plants. The problems concerned are quantitative and qualitative changes in biocenoses, the disturbance or extinction of flora and fauna, physiological changes in organisms and changes in the hydrochemical regime. (Z.M.)

  5. Pulsewidth modulated DC-to-DC power conversion circuits, dynamics, and control designs

    CERN Document Server

    Choi, Byungcho

    2013-01-01

    This is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to

  6. Impact of thermal power generation units on floristic diversity of Kota and its environs

    International Nuclear Information System (INIS)

    Jain, Shuchita; Dadhich, K.

    2001-01-01

    The emissions from thermal power plants have great phytotoxic effects on plants due to changes in their morphology and physiology. A floristic study has been conducted near the Thermal Power Station at Kota in Rajasthan to estimate the impact of emissions from the thermal power plant on biota. It is observed that the whole vegetation, especially the perennial trees and shrubs, growing near the station were severely damaged due to effects of air pollutants emitted from the Thermal Power Station. Analysis of the fly ash reveals its composition as composed of silica, alumina, iron oxide etc. (author)

  7. Color of hot soup modulates postprandial satiety, thermal sensation, and body temperature in young women.

    Science.gov (United States)

    Suzuki, Maki; Kimura, Rie; Kido, Yasue; Inoue, Tomoko; Moritani, Toshio; Nagai, Narumi

    2017-07-01

    The color of food is known to modulate not only consumers' motivation to eat, but also thermal perception. Here we investigated whether the colors of hot soup can influence thermal sensations and body temperature, in addition to the food acceptability and appetite. Twelve young female participants consumed commercial white potage soup, modified to yellow or blue by adding food dyes, at 9 a.m. on 3 separated days. During the test, visual impression (willingness to eat, palatability, comfort, warmth, and anxiety) and thermal sensations were self-reported using visual analog scales. Core (intra-aural) and peripheral (toe) temperatures were continuously recorded 10 min before and 60 min after ingestion. Blue soup significantly decreased willingness to eat, palatability, comfort, and warmth ratings, and significantly increased anxiety feelings compared to the white and yellow soups. After ingestion, the blue soup showed significantly smaller satiety ratings and the tendency of lower thermal sensation scores of the whole body compared to the white and yellow soups. Moreover, a significantly greater increase in toe temperature was found with the yellow soup than the white or blue soup. In conclusion, this study provides new evidence that the colors of hot food may modulate postprandial satiety, thermal sensations and peripheral temperature. Such effects of color may be useful for dietary strategies for individuals who need to control their appetite. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Aerosol absorption measurement with a sinusoidal phase modulating fiber optic photo thermal interferometer

    Science.gov (United States)

    Li, Shuwang; Shao, Shiyong; Mei, Haiping; Rao, Ruizhong

    2016-10-01

    Aerosol light absorption plays an important role in the earth's atmosphere direct and semi-direct radiate forcing, simultaneously, it also has a huge influence on the visibility impairment and laser engineering application. Although various methods have been developed for measuring aerosol light absorption, huge challenge still remains in precision, accuracy and temporal resolution. The main reason is that, as a part of aerosol light extinction, aerosol light absorption always generates synchronously with aerosol light scattering, and unfortunately aerosol light scattering is much stronger in most cases. Here, a novel photo-thermal interferometry is proposed only for aerosol absorption measurement without disturbance from aerosol scattering. The photo-thermal interferometry consists of a sinusoidal phase-modulating single mode fiber-optic interferometer. The thermal dissipation, caused by aerosol energy from photo-thermal conversion when irritated by pump laser through interferometer, is detected. This approach is completely insensitive to aerosol scattering, and the single mode fiber-optic interferometer is compact, low-cost and insensitive to the polarization shading. The theory of this technique is illustrated, followed by the basic structure of the sinusoidal phase-modulating fiber-optic interferometer and demodulation algorithms. Qualitative and quantitative analysis results show that the new photo-thermal interference is a potential approach for aerosol absorption detection and environmental pollution detection.

  9. Vce-based methods for temperature estimation of high power IGBT modules during power cycling - A comparison

    DEFF Research Database (Denmark)

    Amoiridis, Anastasios; Anurag, Anup; Ghimire, Pramod

    2015-01-01

    . This experimental work evaluates the validity and accuracy of two Vce based methods applied on high power IGBT modules during power cycling tests. The first method estimates the chip temperature when low sense current is applied and the second method when normal load current is present. Finally, a correction factor......Temperature estimation is of great importance for performance and reliability of IGBT power modules in converter operation as well as in active power cycling tests. It is common to be estimated through Thermo-Sensitive Electrical Parameters such as the forward voltage drop (Vce) of the chip...

  10. An Optimization Scheduling Model for Wind Power and Thermal Power with Energy Storage System considering Carbon Emission Trading

    Directory of Open Access Journals (Sweden)

    Huan-huan Li

    2015-01-01

    Full Text Available Wind power has the characteristics of randomness and intermittence, which influences power system safety and stable operation. To alleviate the effect of wind power grid connection and improve power system’s wind power consumptive capability, this paper took emission trading and energy storage system into consideration and built an optimization model for thermal-wind power system and energy storage systems collaborative scheduling. A simulation based on 10 thermal units and wind farms with 2800 MW installed capacity verified the correctness of the models put forward by this paper. According to the simulation results, the introduction of carbon emission trading can improve wind power consumptive capability and cut down the average coal consumption per unit of power. The introduction of energy storage system can smooth wind power output curve and suppress power fluctuations. The optimization effects achieve the best when both of carbon emission trading and energy storage system work at the same time.

  11. Potential impact of thermal effluents from Chongqing Fuling nuclear power plant to the Three Gorges Reservoir

    International Nuclear Information System (INIS)

    Han Baohua; Li Jianguo; Ma Binghui; Zhang Yue; Sun Qunli; Hu Yuping

    2012-01-01

    This study is based on the hydrological data near Chongqing Fuling Nuclear Power Plant along the Yangtze River, the present situation of the ecological environment of the Three Gorges Reservoir and the predicted results of thermal effluents from Chongqing Fuling Nuclear Power Plant. The standards of cooling water and the thermal tolerances indexes of aquatic organisms were investigated. The effects of thermal effluents on aquatic organisms were analyzed. The potential impact of Chongqing Fuling nuclear power plant to the Three Gorges Reservoir was explained. The results show that in the most adverse working conditions, the surface temperature near the outfall area is not more than 1℃, the temperature of thermal effluents do not exceed the suitable thermal range of fish breeding, growth and other thermal tolerances indexes. Thermal effluents from nuclear power plant have no influence about fish, plankton and benthic organisms in the Three Gorges Reservoir. (authors)

  12. Verification of the thermal module in the ELESIM code and the associated uncertainty analysis

    International Nuclear Information System (INIS)

    Arimescu, V.I.; Williams, A.F.; Klein, M.E.; Richmond, W.R.; Couture, M.

    1997-09-01

    Temperature is a critical parameter in fuel modelling because most of the physical processes that occur in fuel elements during irradiation are thermally activated. The focus of this paper is the temperature distribution calculation used in the computer code ELESIM, developed at AECL to model the steady-state behaviour of CANDU fuel. A validation procedure for fuel codes is described and applied to ELESIM's thermal calculation.The effects of uncertainties in model parameters, like Uranium Dioxide thermal conductivity, and input variables, such as fuel element linear power, are accounted for through an uncertainty analysis using Response Surface and Monte Carlo techniques

  13. The Impact of Power Switching Devices on the Thermal Performance of a 10 MW Wind Power NPC Converter

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede

    2012-01-01

    Power semiconductor switching devices play an important role in the performance of high power wind energy generation systems. The state-of-the-art device choices in the wind power application as reported in the industry include IGBT modules, IGBT press-pack and IGCT press-pack. Because...

  14. High-Temperature, Wirebondless, Ultra-Compact Wide Bandgap Power Semiconductor Modules for Space Power Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Silicon carbide (SiC) and other wide band-gap semiconductors offer great promise of high power rating, high operating temperature, simple thermal management, and...

  15. Cross-layer combining of power control and adaptive modulation with truncated ARQ for cognitive radios

    Institute of Scientific and Technical Information of China (English)

    CHENG Shi-lun; YANG Zhen

    2008-01-01

    To maximize throughput and to satisfy users' requirements in cognitive radios, a cross-layer optimization problem combining adaptive modulation and power control at the physical layer and truncated automatic repeat request at the medium access control layer is proposed. Simulation results show the combination of power control, adaptive modulation, and truncated automatic repeat request can regulate transmitter powers and increase the total throughput effectively.

  16. Comprehensive Investigation on Current Imbalance among Parallel Chips inside MW-Scale IGBT Power Modules

    DEFF Research Database (Denmark)

    Wu, Rui; Smirnova, Liudmila; Wang, Huai

    2015-01-01

    With the demands for increasing the power rating and improving reliability level of the high power IGBT modules, there are further needs of understanding how to achieve stable paralleling and identical current sharing between the chips. This paper investigates the stray parameters imbalance among...... parallel chips inside the 1.7 kV/1 kA high power IGBT modules at different frequencies by Ansys Q3D parastics extractor. The resulted current imbalance is further confirmed by experimental measurement....

  17. Analysis of Heat Transfer in Power Split Device for Hybrid Electric Vehicle Using Thermal Network Method

    Directory of Open Access Journals (Sweden)

    Jixin Wang

    2014-06-01

    Full Text Available This paper presents a rational prediction of temperature field on the differential hybrid system (DHS based on the thermal network method (TNM. The whole thermal network model is built by considering both the contact thermal resistance between gasket and planet gear and the temperature effect on the physical property parameters of lubricant. The contact thermal resistance is obtained by using the concept of contact branch thermal resistance and G-W elastic model. By building an elaborate thermal network model and computing models for power losses and thermal resistances between components, the whole temperature field of DHS under typical operating condition is predicted. Results show that thermal network method can be effectively used to predict the temperature distribution and the rule of temperature variation, the surface roughness significantly affects contact thermal conduction, and the decrease in the thermal resistance of the natural convection between air and DHS housing can effectively improve the thermal environment of DHS.

  18. Temperature-modulated direct thermoelectric gas sensors: thermal modeling and results for fast hydrocarbon sensors

    International Nuclear Information System (INIS)

    Rettig, Frank; Moos, Ralf

    2009-01-01

    Direct thermoelectric gas sensors are a promising alternative to conductometric gas sensors. For accurate results, a temperature modulation technique in combination with a regression analysis is advantageous. However, the thermal time constant of screen-printed sensors is quite large. As a result, up to now the temperature modulation frequency (20 mHz) has been too low and the corresponding principle-related response time (50 s) has been too high for many applications. With a special design, respecting the physical properties of thermal waves and the use of signal processing similar to a lock-in-amplifier, it is possible to achieve response times of about 1 s. As a result, direct thermoelectric gas sensors with SnO 2 as a gas-sensitive material respond fast and are reproducible to the propane concentration in the ambient atmosphere. Due to the path-independent behavior of the thermovoltage and the temperature, the measured thermopower of two sensors is almost identical

  19. Models for thermal and mechanical monitoring of power transformers

    Energy Technology Data Exchange (ETDEWEB)

    Vilaithong, Rummiya

    2011-07-01

    At present, for economic reasons, there is an increasing emphasis on keeping transformers in service for longer than in the past. A condition-based maintenance using an online monitoring and diagnostic system is one option to ensure reliability of the transformer operation. The key parameters for effectively monitoring equipment can be selected by failure statistics and estimated failure consequences. In this work, two key aspects of transformer condition monitoring are addressed in depth: thermal behaviour and behaviour of on-load tap changers. In the first part of the work, transformer thermal behaviour is studied, focussing on top-oil temperatures. Through online comparison of a measured value of the top-oil temperature and its calculated value, some rapidly developing failures in power transformers such as malfunction of the cooling unit may be detected. Predictions of top-oil temperature can be obtained by means of a mathematical model. Long-term investigations on some dynamic top-oil temperature models are presented for three different types of transformer units. The last-state top-oil temperature, load current, ambient temperature and the operating state of pumps and fans are applied as inputs of the top-oil temperature models. In the fundamental physical models presented, some constant parameters are required and can be estimated using a least-squares optimization technique. Multilayer Feed-forward and Recurrent neural network models are also proposed and investigated. The neural network models are trained with three different Backpropagation training algorithms: Levenberg-Marquardt, Scaled Conjugate Gradient and Automated Bayesian Regularization. The effect of varying operating conditions of the cooling units and the non-steady-state behaviour of loading conditions, as well as ambient temperature are noted. Results show sophisticated temperature prediction is possible using the neural network models that is generally more accurate than with the physical

  20. A minimization procedure for estimating the power deposition and heat transport from the temperature response to auxiliary power modulation

    International Nuclear Information System (INIS)

    Eester, Dirk van

    2004-01-01

    A method commonly used for determining where externally launched power is absorbed inside a tokamak plasma is to examine the temperature response to modulation of the launched power. Strictly speaking, this response merely provides a first good guess of the actual power deposition rather than the deposition profile itself: not only local heat sources but also heat losses and heat wave propagation affect the temperature response at a given position. Making use of this, at first sight non-desirable, effect modulation becomes a useful tool for conducting transport studies. In this paper a minimization method based on a simple conduction-convection model is proposed for deducing the power deposition and transport characteristics from the experimentally measured (electron) energy density response to a modulation of the auxiliary heating power. An L-mode JET example illustrates the potential of the technique

  1. Thermal Management of Power Electronics and Electric Motors for Electric-Drive Vehicles (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Narumanchi, S.

    2014-09-01

    This presentation is an overview of the power electronics and electric motor thermal management and reliability activities at NREL. The focus is on activities funded by the Department of Energy Vehicle Technologies Office Advanced Power Electronics and Electric Motors Program.

  2. Measuring modules for the research of compensators of reactive power with voltage stabilization in MATLAB

    Science.gov (United States)

    Vlasayevsky, Stanislav; Klimash, Stepan; Klimash, Vladimir

    2017-10-01

    A set of mathematical modules was developed for evaluation the energy performance in the research of electrical systems and complexes in the MatLab. In the electrotechnical library SimPowerSystems of the MatLab software, there are no measuring modules of energy coefficients characterizing the quality of electricity and the energy efficiency of electrical apparatus. Modules are designed to calculate energy coefficients characterizing the quality of electricity (current distortion and voltage distortion) and energy efficiency indicators (power factor and efficiency) are presented. There are described the methods and principles of building the modules. The detailed schemes of modules built on the elements of the Simulink Library are presented, in this connection, these modules are compatible with mathematical models of electrical systems and complexes in the MatLab. Also there are presented the results of the testing of the developed modules and the results of their verification on the schemes that have analytical expressions of energy indicators.

  3. Modeling of Short-Circuit-Related Thermal Stress in Aged IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Iannuzzo, Francesco; Uhrenfeldt, Christian

    2017-01-01

    In this paper, the thermal stress on bond wires of aged IGBT modules under short-circuit conditions has been studied with respect to different solder delamination levels. To ensure repeatable test conditions, ad-hoc DBC (direct bond copper) samples with delaminated solder layers have been purposely...... in the surface temperature distribution, which confirms the hypothesis that short-circuit events produce significantly uneven stresses on bond wires....

  4. Prediction of Short-Circuit-Related Thermal Stress in Aged IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Iannuzzo, Francesco; Uhrenfeldt, Christian

    2016-01-01

    In this paper, the thermal stress on bond wires of aged IGBT modules under short-circuit conditions has been studied with respect to different solder delamination levels. To ensure repeatable test conditions, ad-hoc DBC (direct bond copper) samples with delaminated solder layers have been purposely...... in the surface temperature distribution which confirms the hypothesis that short-circuit events produce significantly uneven stresses on bond wires....

  5. Multi Carrier Modulation Audio Power Amplifier with Programmable Logic

    DEFF Research Database (Denmark)

    Christiansen, Theis; Andersen, Toke Meyer; Knott, Arnold

    2009-01-01

    While switch-mode audio power amplifiers allow compact implementations and high output power levels due to their high power efficiency, they are very well known for creating electromagnetic interference (EMI) with other electronic equipment. To lower the EMI of switch-mode (class D) audio power a...

  6. Study on Effect of Junction Temperature Swing Duration on Lifetime of Transfer Molded Power IGBT Modules

    DEFF Research Database (Denmark)

    Choi, Uimin; Blaabjerg, Frede; Jørgensen, Søren

    2017-01-01

    levels are presented. This study enables to include the tΔTj effect on lifetime model of IGBT modules for its lifetime estimation and it may result in improved lifetime prediction of IGBT modules under given mission profiles of converters. A postfailure analysis of the tested IGBT modules is also......In this paper, the effect of junction temperature swing duration on lifetime of transfer molded power insulated gate bipolar transistor (IGBT) modules is studied and a relevant lifetime factor is modeled. This study is based on 39 accelerated power cycling test results under six different...

  7. Gravity modulation of thermal instability in a viscoelastic fluid saturated anisotropic porous medium

    Energy Technology Data Exchange (ETDEWEB)

    Bhadauria, Beer S. [Babasaheb Bhimrao Ambedkar Univ., Lucknow (India). Dept. of Applied Mathematics and Statistics; Banaras Hindu Univ., Varanasi (India). Dept. of Mathematics; Srivastava, Atul K. [Banaras Hindu Univ., Varanasi (India). Dept. of Mathematics; Sacheti, Nirmal C.; Chandran, Pallath [Sultan Qaboos Univ., Muscat (Oman). Dept. of Mathematics

    2012-01-15

    The present paper deals with a thermal instability problem in a viscoelastic fluid saturating an anisotropic porous medium under gravity modulation. To find the gravity modulation effect, the gravity field is considered in two parts: a constant part and an externally imposed time-dependent periodic part. The time-dependent part of the gravity field, which can be realized by shaking the fluid, has been represented by a sinusoidal function. Using Hill's equation and the Floquet theory, the convective threshold has been obtained. It is found that gravity modulation can significantly affect the stability limits of the system. Further, we find that there is a competition between the synchronous and subharmonic modes of convection at the onset of instability. Effects of various parameters on the onset of instability have also been discussed. (orig.)

  8. 25Gb/s 1V-driving CMOS ring modulator with integrated thermal tuning.

    Science.gov (United States)

    Li, Guoliang; Zheng, Xuezhe; Yao, Jin; Thacker, Hiren; Shubin, Ivan; Luo, Ying; Raj, Kannan; Cunningham, John E; Krishnamoorthy, Ashok V

    2011-10-10

    We report a high-speed ring modulator that fits many of the ideal qualities for optical interconnect in future exascale supercomputers. The device was fabricated in a 130 nm SOI CMOS process, with 7.5 μm ring radius. Its high-speed section, employing PN junction that works at carrier-depletion mode, enables 25 Gb/s modulation and an extinction ratio >5 dB with only 1V peak-to-peak driving. Its thermal tuning section allows the device to work in broad wavelength range, with a tuning efficiency of 0.19 nm/mW. Based on microwave characterization and circuit modeling, the modulation energy is estimated ~7 fJ/bit. The whole device fits in a compact 400 μm2 footprint.

  9. Pressurized thermal shock analysis in German nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Stefan; Braun, Michael [TUEV NORD Nuclear, Hannover (Germany)

    2015-03-15

    For more than 30 years TUeV NORD is a competent consultant in nuclear safety is-sues giving expert third party opinion to our clients. According to the German regulations the safety against brittle fracture has to be proved for the reactor pressure vessel (RPV) and with a new level of knowledge the proof has to be continuously updated with the development in international codes and standards like ASME, BS and RCC-M. The load of the RPV is a very complex transient pressure and temperature situation. Today these loading conditions can be modeled by thermal hydraulic calculations and new experimental results much more detailed than in the construction phase of German Nuclear Power Plants in the 1980s. Therefore, the proof against brittle fracture from the construction phase had to be updated for all German Nuclear Power Plants with the new findings of the loading conditions especially for a postulated small leakage in the main coolant line. The RPV consists of ferritic base material (about 250 mm) and austenitic cladding (about 6 mm) at the inner side. The base material and the cladding have different physical properties which have to be considered temperature dependently in the cal-culations. Radiation-embrittlement effects on the material are to be respected in the fracture mechanics assessment. The regions of the RPV of special interest are the core weld, the inlet and outlet nozzle region and the flange connecting weld zone. The fracture mechanics assessment is performed for normal and abnormal operating conditions and for accidents like LOCA (Loss of Coolant Accident). In this paper the German approach to fracture mechanics assessment to brittle fracture will be discussed from the point of view of a third party organization.

  10. A Wind Power Plant with Thermal Energy Storage for Improving the Utilization of Wind Energy

    Directory of Open Access Journals (Sweden)

    Chang Liu

    2017-12-01

    Full Text Available The development of the wind energy industry is seriously restricted by grid connection issues and wind energy generation rejections introduced by the intermittent nature of wind energy sources. As a solution of these problems, a wind power system integrating with a thermal energy storage (TES system for district heating (DH is designed to make best use of the wind power in the present work. The operation and control of the system are described in detail. A one-dimensional system model of the system is developed based on a generic model library using the object-oriented language Modelica for system modeling. Validations of the main components of the TES module are conducted against experimental results and indicate that the models can be used to simulate the operation of the system. The daily performance of the integrated system is analyzed based on a seven-day operation. And the influences of system configurations on the performance of the integrated system are analyzed. The numerical results show that the integrated system can effectively improve the utilization of total wind energy under great wind power rejection.

  11. Design of the power supply system for the plasma current modulation on J-TEXT tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, M.; Shao, J.; Ma, S.X., E-mail: mashaoxiang@hust.edu.cn; Liang, X.; Yu, K.X.; Pan, Y.

    2016-10-15

    Highlights: • A modification scheme of heating field power supply system for plasma current modulation. • High-power fast control power supply with multilevel cascade circuit. • Restraining circulating current with coupled inductors in cyclic symmetric structure. - Abstract: In order to further study the influence of current modulation parameters on suppressing tearing instability, the plasma current should be modulated in a wider range. So a modification scheme is designed to improve the performance of ohmic heating power supply system on J-TEXT tokamak. A multilevel cascade circuit with carrier phase-shifted PWM technique has been proposed. Coupled inductors are connected in the form of cyclic symmetry to restrain the circulating current caused by multiple paralleled branches. The simulation proves this proposed current modulation power supply system matches output requirement and achieves good current sharing effect. Finally, a prototype is designed, and the experiment results can verify the correctness of the simulation model well.

  12. Comparison of the effects of nuclear power plants and thermal power plants on the environment

    International Nuclear Information System (INIS)

    Sivintsev, Yu.V.; Teverovskij, E.N.

    1976-01-01

    A comparison of ecological effects produced by a thermal power station (TPS) and a nuclear power plant (NPP) of similar electric capacity has been made. The ecological advantages of NPP over TPS are revealed in analysis of aerosol and gas blow-out and its danger for the environment. From the above data it follows that TPS as compared with NPP of similar electric capacity produces a 100 and 1000 fold higher air pollution effect than the latter. The dose of TPS radiation effect is minimum 500 times higher than that of NPP at normal operation. Large-scale construction of NPP is one of the most perfect means of atmosphere protection against harmful industrial discharges

  13. Thermal Expansion of Vitrified Blood Vessels Permeated with DP6 and Synthetic Ice Modulators

    Science.gov (United States)

    Eisenberg, David P.; Taylor, Michael J.; Jimenez-Rios, Jorge L.; Rabin, Yoed

    2014-01-01

    This study provides thermal expansion data for blood vessels permeated with the cryoprotective cocktail DP6, when combined with selected synthetic ice modulators (SIMs): 12% polyethylene glycol 400, 6% 1,3-cyclohexanediol, and 6% 2,3-butanediol. The general classification of SIMs includes molecules that modulate ice nucleation and growth, or possess properties of stabilizing the amorphous state, by virtue of their chemical structure and at concentrations that are not explained on a purely colligative basis. The current study is part of an ongoing effort to characterize thermo-mechanical effects on structural integrity of cryopreserved materials, where thermal expansion is the driving mechanism to thermo-mechanical stress. This study focuses on the lower part of the cryogenic temperature range, where the cryoprotective agent (CPA) behaves as a solid for all practical applications. By combining results obtained in the current study with literature data on the thermal expansion in the upper part of the cryogenic temperature range, unified thermal expansion curves are presented. PMID:24769313

  14. Nanoscale phase engineering of thermal transport with a Josephson heat modulator

    Science.gov (United States)

    Fornieri, Antonio; Blanc, Christophe; Bosisio, Riccardo; D'Ambrosio, Sophie; Giazotto, Francesco

    2016-03-01

    Macroscopic quantum phase coherence has one of its pivotal expressions in the Josephson effect, which manifests itself both in charge and energy transport. The ability to master the amount of heat transferred through two tunnel-coupled superconductors by tuning their phase difference is the core of coherent caloritronics, and is expected to be a key tool in a number of nanoscience fields, including solid-state cooling, thermal isolation, radiation detection, quantum information and thermal logic. Here, we show the realization of the first balanced Josephson heat modulator designed to offer full control at the nanoscale over the phase-coherent component of thermal currents. Our device provides magnetic-flux-dependent temperature modulations up to 40 mK in amplitude with a maximum of the flux-to-temperature transfer coefficient reaching 200 mK per flux quantum at a bath temperature of 25 mK. Foremost, it demonstrates the exact correspondence in the phase engineering of charge and heat currents, breaking ground for advanced caloritronic nanodevices such as thermal splitters, heat pumps and time-dependent electronic engines.

  15. Account of External Cooling Medium Temperature while Modeling Thermal Processes in Power Oil-Immersed Transformers

    OpenAIRE

    Yu. A. Rounov; O. G. Shirokov; D. I. Zalizny; D. M. Los

    2004-01-01

    The paper proposes a thermal model of a power oil-immersed transformer as a system of four homogeneous bodies: winding, oil, core and cooling medium. On the basis of experimental data it is shown that such model describes more precisely actual thermal processes taking place in a transformer than the thermal model accepted in GOST 14209-85.

  16. Account of External Cooling Medium Temperature while Modeling Thermal Processes in Power Oil-Immersed Transformers

    Directory of Open Access Journals (Sweden)

    Yu. A. Rounov

    2004-01-01

    Full Text Available The paper proposes a thermal model of a power oil-immersed transformer as a system of four homogeneous bodies: winding, oil, core and cooling medium. On the basis of experimental data it is shown that such model describes more precisely actual thermal processes taking place in a transformer than the thermal model accepted in GOST 14209-85.

  17. Sandia Laboratories in-house activities in support of solar thermal large power applications

    Science.gov (United States)

    Mar, R. W.

    1980-01-01

    The development of thermal energy storage subsystems for solar thermal large power applications is described. The emphasis is on characterizing the behavior of molten nitrate salts with regard to thermal decomposition, environmental interactions, and corrosion. Electrochemical techniques to determine the ionic species in the melt and for use in real time studies of corrosion are also briefly discussed.

  18. Comparative assessment of 3.3kV/400A SiC MOSFET and Si IGBT power modules

    DEFF Research Database (Denmark)

    Ionita, Claudiu; Nawaz, Muhammad; Ilves, Kalle

    2017-01-01

    In this paper, a comparative evaluation between a commercial 3.3 kV/400 A Si-IGBT and a 3.3 kV/400 A SiC MOSFET power module in half-bridge configuration is presented. With a constant current of 250 A, a lower forward voltage (VDS) drop of 1.6 V is obtained for SiC MOSFET at 300 K compared to Si ...... the pulse duration was increased to 4 μs, where a short-circuit energy of 9.1 J was obtained. The cause of the failure is the thermal runaway leading to a drain-source short....

  19. ATLAS ITk short-strip stave prototype module with integrated DCDC powering and control

    CERN Document Server

    AUTHOR|(SzGeCERN)397167; The ATLAS collaboration

    2017-01-01

    During the Phase II upgrade, the ATLAS detector at the LHC will be upgraded with a new Inner Tracker (ITk) detector. The ITk prototype barrel module design has adopted an integrated low mass assembly featuring single-sided flexible circuits, with readout ASICs, glued to the silicon strip sensor. Further integration has been achieved by the attachment of module DCDC powering, a HV sensor biasing switch and autonomous monitoring and control to the sensor. This low mass integrated module approach benefits further in a reduced width stave structure to which the modules are attached. The results of preliminary electrical tests of such an integrated module are presented.

  20. Design and construction of tetrode tube modulator for high power electron accelerator

    Directory of Open Access Journals (Sweden)

    A M Poursaleh

    2015-09-01

    Full Text Available In this paper, a high power tetrode tube (TH781-200kW, cw modulator is designed and implemented. This modulator is used for a part of RF system of the first Iranian high power electron accelerator project with similar structure to Rhodotron accelerator. Regarding to the level of sensitive and importance of TH781 tube the modulator system designed with high accuracy. So beside of power supplies design the control circuits for protection of the tube have been considered. The results of test and operation of this system that have been constructed in Iran for fist time is very satisfactory