DOCSLIB.ORG

Experiment 6 ~ Joule Heating of a Resistor

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Experiment 6 ~ Joule Heating of a Resistor Introduction: The power P absorbed in an electrical resistor of resistance R, current I, and voltage V is given by P = I2R = V2/R = VI. Despite the fact that it has units of power, it is commonly referred to as joule heat. A given amount of electrical energy absorbed in the resistor (in units of joules) produces a fixed amount of heat (in units of calories). The constant ratio between the two has the value 4.184 J/cal and is numerically equivalent to the specific heat capacity of water. In this lab, an electric coil will be immersed in water in a calorimeter, and a known amount of electrical energy will be input to the coil. Measurements of the heat produced will be used to accomplish the following objectives: 1. Demonstrate that the rise in temperature of the system is proportional to the electrical energy input. 2. Determination of an experimental value for J and comparison of that value with the known value. Theory: When a resistor of resistance R has a current I at voltage V, the power absorbed in the resistor is P = I2R = V2/R = VI (1) Power is energy per unit time, and if the power is constant, the energy U delivered in time t is given by: U = Pt (2) Substituting equation 1 into equation 2 gives the following expression for the electrical energy: U = VIt (3) When a resistor absorbs electrical energy, it dissipates this energy in the form of heat Q. If the resistor is placed in the calorimeter, the amount of heat produced can be measured when it is absorbed in the calorimeter. Consider the experimental arrangement shown in Figure 5.1, which a resistor coil (also called and “immersion heater”) is immersed in the water in a calorimeter. The heat Q produced in the resister is absorbed by the water, calorimeter cup, and the resistor coil itself. This heat Q produces a rise in temperature ΔT. The heat Q is related to ΔT. The heat Q is related to ΔT by: Q = (mwcw + mccc + mrcr) ΔT (4) The mc’s are the masses and specific heats of the water, the calorimeter, and the resistor. Let mc stand for the sum of the product of the mass and the specific heat for the three objects that absorb the heat. In those terms the heat Q is given by the following: Q = mcΔT (5) The electrical energy absorbed in the resistor is completely converted to heat. The equality of those two energies is expressed as U (J) = J (J/cal) Q (cal) (6) J represents the conversion factor from joules to calories. Using the expression for U and Q from equations 3 and 5 in equation 6 leads to VIt(J) = J(J/cal) mcΔT(cal) (7) Figure 1: Experimental arrangement and circuit diagram for the calorimetric measurement of the heat produced in an immersion heater by an electrical current. Suppose that a fixed current and voltage are applied to the resistor in a calorimeter, and the temperature rise ΔT is measured as a measured as a function of the time t. Equation 7 predicts that a graph with VIt(J) as the y-axis and mcΔT(cal) as the x-axis should produce a straight line with J as the slope. Equipment: Immersion heater coil to fit standard calorimeter Calorimeter and thermometer Direct-current power supply (0.5 A) Ammeter (0-5 A), Voltmeter (0-10V) Laboratory timer Laboratory balance Procedure: The procedure outlined below is designed to also use Data Studio with a thermometer attached. The program will take continuous measurements and store the data in a table with the time. You may save the data and analyze it using Excel. For this part of the lab you will use the laptop connected to your set up. Save the Data Studio file to the desktop. You will have to change the file formate to all files and save as a .ds file. The file can be downloaded from the Physics lab site at: http://www.umsl.edu/~physics/lab/electricitylab/12-lab6.html. Once you have the laptop on and the sensors plugged in you can double click on the saved file to open the Data Studio program. If you need to find it later the program can be found in the ‘Education’ folder under the programs in the start menu. To start taking measurements, click on the run button on the upper tool bar. The lab TA will provide more instruction. If you make a mistake with the program you can start over by closing the program without saving and opening it again from the Desktop. An empty graph should appear; to start the measurement press the green ‘play’ button at the top of the screen. To stop the measurement press the ‘stop button’ (the same button). Determine the mass mc of the calorimeter cup and record it in the Data Table. You may neglect the mass of the resistor coil since the quantity mrcr∆T is a very small fraction of the total Q in equation 4. Place enough water (about 150-200 mL) in the calorimeter cup to immerse the resistor coil completely. The water temperature should be a few degrees below room temperature. Be sure that the coil is completely covered by the water, but do not use any more water than is necessary. Determine the mass of the water plus the calorimeter cup and record it in the Data Table. Determine the mass of the water by subtraction and record it as mw in the Data Table. Place the immersion heater in the calorimeter cup and construct the circuit shown in Figure 5.1. Check again that the immersion heat is below the water level. If it is not, add some more water and determine the mass of the water again. Turn on the power supply and adjust the current to .5 A. Do this quickly and then turn off the supply with the output level still adjusted to the setting that produced the desired current. Do not allow the supply to stay on long enough to appreciably heat the water. Stir the system several minutes to allow it to come to equilibrium. Determine the initial temperature Ti and record it in the Data Table. Estimate the thermometer readings to the nearest 0.1°C for all temperature measurements. With the power supply still set to the output level required to produce 0.5 A, turn on the power supply and simultaneously start the laboratory timer. Record the initial values of the current I and the voltage V in the Data Table. Let the timer run continuously and stir the system often. Measure and record the temperature T, the current I, and the Voltage V every 60 s for 8 minutes. Record all data in the Data Table. Calculations: Calculate the quantity mc, where mc = mwcw + mccc and record it in the Calculations Table. Calculate the temperature rise of ΔT above the initial temperature Ti from ΔT = T – Ti for each of the measured values of T and record the results in the Calculations Table. Calculate the quantity mcΔT for each case and record the results in the Calculations table. For each measurement of the voltage V and current I calculate the product VI and record the results in the Calculations Table. Calculate the mean and standard deviation σVI for the values of VI and record the results in the calculations Table. Calculate the quantity for each time t and record the results in the Calculations Table. Perform a linear least squares fit to the data with as the y-axis and mcΔT as the x-axis. Determine the slope Jexp, the intercept A, and the correlation coefficient R and record them in the Calculations Table. Calculate the percentage error in the value of Jexp compared to the known value of J = 4.184 J/cal. Graphs: Graph the data with VIt as the ordinate (y-axis) and mcΔT as the abscissa (x-axis). Also show on the graph the straight line obtained from the linear least squares fit. Table 1 Mass Calorimeter = g Ti = °C Mass Calorimeter + Mass Water = c for calorimeter = cal/(g °C) g Mass Water = g c for water = cal/(g °C) t(s) V (V) I(A) T(°C) 0 60 120 180 240 300 360 420 480 mc = mwcw + mccc= ______________(cal/°C) Table 2 ΔT(°C) mcΔT (cal) VI (W) VI t (J) 0 0 0 = W σVI = W Jexp = J/cal A = J R= Percentage error in experimental J = Questions: When the electrical power input is approximately constant, the temperature rise of the system should be proportional to the elapsed time. Does your data confirm this expectation? State the evidence for your answer. What is accuracy of your experiment value for J? Does the correlation coefficient of the least squares fit to the data indicate strong evidence for linearity in this data? How long from the original starting time would it have taken to achieve a temperature of 50.0°C with the experimental arrangement you used? Show your work. Assuming that one used the same heating coil and that its resistance did not change, how much would the power be increased if the voltage were increased by 50%? Show your work. Suppose that some liquid other than water were used in the calorimeter. If the liquid had a specific heat of 0.25 cal/g-°C, would that tend to improve the results, make them worse, or have no effect on them? Explain clearly the reasoning behind your answer.
Recommended publications
  • Printer Tech Tips—Cause & Effects of Static Electricity in Paper

    Printer Tech Tips—Cause & Effects of Static Electricity in Paper

    Printer Tech Tips Cause & Effects of Static Electricity in Paper Problem The paper has developed a static electrical charge causing an abnormal sheet-to- sheet or sheet-to-material attraction which is difficult to separate. This condition may result in feeder trip-offs, print voids from surface contamination, ink offset, Sappi Printer Technical Service or poor sheet jog in the delivery. 877 SappiHelp (727 7443) Description Static electricity is defined as a non-moving, non-flowing electrical charge or in simple terms, electricity at rest. Static electricity becomes visible and dynamic during the brief moment it sparks a discharge and for that instant it’s no longer at rest. Lightning is the result of static discharge as is the shock you receive just before contacting a grounded object during unusually dry weather. Matter is composed of atoms, which in turn are composed of protons, neutrons, and electrons. The number of protons and neutrons, which make up the atoms nucleus, determine the type of material. Electrons orbit the nucleus and balance the electrical charge of the protons. When both negative and positive are equal, the charge of the balanced atom is neutral. If electrons are removed or added to this configuration, the overall charge becomes either negative or positive resulting in an unbalanced atom. Materials with high conductivity, such as steel, are called conductors and maintain neutrality because their electrons can move freely from atom to atom to balance any applied charges. Therefore, conductors can dissipate static when properly grounded. Non-conductive materials, or insulators such as plastic and wood, have the opposite property as their electrons can not move freely to maintain balance.
  • 3-D Electromagnetic Radiative Non-Newtonian Nanofluid Flow With

    3-D Electromagnetic Radiative Non-Newtonian Nanofluid Flow With

    www.nature.com/scientificreports OPEN 3‑D electromagnetic radiative non‑Newtonian nanofuid fow with Joule heating and higher‑order reactions in porous materials Amel A. Alaidrous1* & Mohamed R. Eid2,3* The aim of this work is to discuss the efect of mth‑order reactions on the magnetic fow of hyperbolic tangent nanofuid through extending surface in a porous material with thermal radiation, several slips, Joule heating, and viscous dissipation. In order to convert non‑linear partial diferential governing equations into ordinary ones, a technique of similarity transformations has been implemented and then solved using the OHAM (optimal homotopy analytical method). The outcomes of novel efective parameters on the non‑dimensional interesting physical quantities are established utilizing the tabular and pictorial outlines. After a comparison with previous literature studies, the results were fnely compliant. The study explores that the reduced Nusselt number is diminished for the escalating values of radiation, porosity, and source (sink) parameters. It is found that the order of the chemical reaction m = 2 is dominant in concentration as well as mass transfer in both destructive and generative reactions. When m reinforces for a destructive reaction, mass transfer is reduced with 34.7% and is stabled after η = 3. In the being of the destructive reaction and Joule heating, the nanofuid’s temperature is enhanced. Abbreviations a, b Constants (–) B0 Magnetic parameter C Concentration (mol/m3) cp Specifc heat C Free stream concentration (mol/m3)
  • A Review of Energy Storage Technologies' Application

    A Review of Energy Storage Technologies' Application

    sustainability Review A Review of Energy Storage Technologies’ Application Potentials in Renewable Energy Sources Grid Integration Henok Ayele Behabtu 1,2,* , Maarten Messagie 1, Thierry Coosemans 1, Maitane Berecibar 1, Kinde Anlay Fante 2 , Abraham Alem Kebede 1,2 and Joeri Van Mierlo 1 1 Mobility, Logistics, and Automotive Technology Research Centre, Vrije Universiteit Brussels, Pleinlaan 2, 1050 Brussels, Belgium; [email protected] (M.M.); [email protected] (T.C.); [email protected] (M.B.); [email protected] (A.A.K.); [email protected] (J.V.M.) 2 Faculty of Electrical and Computer Engineering, Jimma Institute of Technology, Jimma University, Jimma P.O. Box 378, Ethiopia; [email protected] * Correspondence: [email protected]; Tel.: +32-485659951 or +251-926434658 Received: 12 November 2020; Accepted: 11 December 2020; Published: 15 December 2020 Abstract: Renewable energy sources (RESs) such as wind and solar are frequently hit by fluctuations due to, for example, insufficient wind or sunshine. Energy storage technologies (ESTs) mitigate the problem by storing excess energy generated and then making it accessible on demand. While there are various EST studies, the literature remains isolated and dated. The comparison of the characteristics of ESTs and their potential applications is also short. This paper fills this gap. Using selected criteria, it identifies key ESTs and provides an updated review of the literature on ESTs and their application potential to the renewable energy sector. The critical review shows a high potential application for Li-ion batteries and most fit to mitigate the fluctuation of RESs in utility grid integration sector.
  • 3.Joule's Experiments

    3.Joule's Experiments

    The Force of Gravity Creates Energy: The “Work” of James Prescott Joule http://www.bookrags.com/biography/james-prescott-joule-wsd/ James Prescott Joule (1818-1889) was the son of a successful British brewer. He tinkered with the tools of his father’s trade (particularly thermometers), and despite never earning an undergraduate degree, he was able to answer two rather simple questions: 1. Why is the temperature of the water at the bottom of a waterfall higher than the temperature at the top? 2. Why does an electrical current flowing through a conductor raise the temperature of water? In order to adequately investigate these questions on our own, we need to first define “temperature” and “energy.” Second, we should determine how the measurement of temperature can relate to “heat” (as energy). Third, we need to find relationships that might exist between temperature and “mechanical” energy and also between temperature and “electrical” energy. Definitions: Before continuing, please write down what you know about temperature and energy below. If you require more space, use the back. Temperature: Energy: We have used the concept of gravity to show how acceleration of freely falling objects is related mathematically to distance, time, and speed. We have also used the relationship between net force applied through a distance to define “work” in the Harvard Step Test. Now, through the work of Joule, we can equate the concepts of “work” and “energy”: Energy is the capacity of a physical system to do work. Potential energy is “stored” energy, kinetic energy is “moving” energy. One type of potential energy is that induced by the gravitational force between two objects held at a distance (there are other types of potential energy, including electrical, magnetic, chemical, nuclear, etc).
  • Electric Permittivity of Carbon Fiber

    Electric Permittivity of Carbon Fiber

    Carbon 143 (2019) 475e480 Contents lists available at ScienceDirect Carbon journal homepage: www.elsevier.com/locate/carbon Electric permittivity of carbon fiber * Asma A. Eddib, D.D.L. Chung Composite Materials Research Laboratory, Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, 14260-4400, USA article info abstract Article history: The electric permittivity is a fundamental material property that affects electrical, electromagnetic and Received 19 July 2018 electrochemical applications. This work provides the first determination of the permittivity of contin- Received in revised form uous carbon fibers. The measurement is conducted along the fiber axis by capacitance measurement at 25 October 2018 2 kHz using an LCR meter, with a dielectric film between specimen and electrode (necessary because an Accepted 11 November 2018 LCR meter is not designed to measure the capacitance of an electrical conductor), and with decoupling of Available online 19 November 2018 the contributions of the specimen volume and specimen-electrode interface to the measured capaci- tance. The relative permittivity is 4960 ± 662 and 3960 ± 450 for Thornel P-100 (more graphitic) and Thornel P-25 fibers (less graphitic), respectively. These values are high compared to those of discon- tinuous carbons, such as reduced graphite oxide (relative permittivity 1130), but are low compared to those of steels, which are more conductive than carbon fibers. The high permittivity of carbon fibers compared to discontinuous carbons is attributed to the continuity of the fibers and the consequent substantial distance that the electrons can move during polarization. The P-100/P-25 permittivity ratio is 1.3, whereas the P-100/P-25 conductivity ratio is 67.
  • Joule Heating of the South Polar Terrain on Enceladus K

    Joule Heating of the South Polar Terrain on Enceladus K

    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 116, E04010, doi:10.1029/2010JE003776, 2011 Joule heating of the south polar terrain on Enceladus K. P. Hand,1 K. K. Khurana,2 and C. F. Chyba3 Received 12 November 2010; revised 1 February 2011; accepted 13 February 2011; published 27 April 2011. [1] We report that Joule heating in Enceladus, resulting from the interaction of Enceladus with Saturn’s magnetic field, may account for 150 kW to 52 MW of power through Enceladus. Electric currents passing through subsurface channels of low salinity and just a few kilometers in depth could supply a source of power to the south polar terrain, providing a small but previously unaccounted for contribution to the observed heat flux and plume activity. Studies of the electrical heating of Jupiter’s moon Europa have concluded that electricity is a negligible heating source since no connection between the conductive subsurface and Alfvén currents has been observed. Here we show that, contrary to results for the Jupiter system, electrical heating may be a source of internal energy for Enceladus, contributing to localized heating, production of water vapor, and the persistence of the “tiger stripes.” This contribution is of order 0.001–0.25% of the total observed heat flux, and thus, Joule heating cannot explain the total south polar terrain heat anomaly. The exclusion of salt ions during refreezing serves to enhance volumetric Joule heating and could extend the lifetime of liquid water fractures in the south polar terrain. Citation: Hand, K. P., K. K. Khurana, and C. F. Chyba (2011), Joule heating of the south polar terrain on Enceladus, J.
  • Work and Energy Summary Sheet Chapter 6

    Work and Energy Summary Sheet Chapter 6

    Work and Energy Summary Sheet Chapter 6 Work: work is done when a force is applied to a mass through a displacement or W=Fd. The force and the displacement must be parallel to one another in order for work to be done. F (N) W =(Fcosθ)d F If the force is not parallel to The area of a force vs. the displacement, then the displacement graph + W component of the force that represents the work θ d (m) is parallel must be found. done by the varying - W d force. Signs and Units for Work Work is a scalar but it can be positive or negative. Units of Work F d W = + (Ex: pitcher throwing ball) 1 N•m = 1 J (Joule) F d W = - (Ex. catcher catching ball) Note: N = kg m/s2 • Work – Energy Principle Hooke’s Law x The work done on an object is equal to its change F = kx in kinetic energy. F F is the applied force. 2 2 x W = ΔEk = ½ mvf – ½ mvi x is the change in length. k is the spring constant. F Energy Defined Units Energy is the ability to do work. Same as work: 1 N•m = 1 J (Joule) Kinetic Energy Potential Energy Potential energy is stored energy due to a system’s shape, position, or Kinetic energy is the energy of state. motion. If a mass has velocity, Gravitational PE Elastic (Spring) PE then it has KE 2 Mass with height Stretch/compress elastic material Ek = ½ mv 2 EG = mgh EE = ½ kx To measure the change in KE Change in E use: G Change in ES 2 2 2 2 ΔEk = ½ mvf – ½ mvi ΔEG = mghf – mghi ΔEE = ½ kxf – ½ kxi Conservation of Energy “The total energy is neither increased nor decreased in any process.
  • Active Short Circuit - Chassis Short Characterization and Potential Mitigation Technique for the MMRTG

    Active Short Circuit - Chassis Short Characterization and Potential Mitigation Technique for the MMRTG

    Jet Propulsion Laboratory California Institute of Technology Multi-Mission RTG Active Short Circuit - Chassis Short Characterization and Potential Mitigation Technique for the MMRTG February 25, 2015 Gary Bolotin1 Nicholas Keyawa1 1Jet Propulsion Laboratory, California Institute of Technology 1 Jet Propulsion Laboratory California Institute of Technology Agenda Multi-Mission RTG • Introduction – MMRTG – Internal MMRTG Chassis Shorts • Active Short Circuit Purpose • Active Short Circuit Theory • Active Short Design and Component Layout • Conclusion and Future Work 2 Jet Propulsion Laboratory California Institute of Technology Introduction – MMRTG Multi-Mission RTG • The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) utilizes a combination of PbTe, PbSnTe, and TAGS thermoelectric couples to produce electric current from the heat generated by the radioactive decay of plutonium – 238. 3 Jet Propulsion Laboratory Introduction – Internal MMRTG Chassis California Institute of Technology Shorts Multi-Mission RTG • Shorts inside the MMRTG between the electrical power circuit and the MMRTG chassis have been detected via isolation checks and/or changes in the bus balance voltage. • Example location of short shown below MMRTG Chassis Internal MMRTG Short 4 Jet Propulsion Laboratory California Institute of Technology Active Short Circuit Purpose Multi-Mission RTG • The leading hypothesis suggests that the FOD which is causing the internal shorts are extremely small pieces of material that could potentially melt and/or sublimate away given a sufficient amount of current. • By inducing a controlled second short (in the presence of an internal MMRTG chassis short), a significant amount of current flow can be generated to achieve three main design goals: 1) Measure and characterize the MMRTG internal short to chassis, 2) Safely determine if the MMRTG internal short can be cleared in the presence of another controlled short 3) Quantify the amount of energy required to clear the MMRTG internal short.
  • Re-Examining the Role of Nuclear Fusion in a Renewables-Based Energy Mix

    Re-Examining the Role of Nuclear Fusion in a Renewables-Based Energy Mix

    Re-examining the Role of Nuclear Fusion in a Renewables-Based Energy Mix T. E. G. Nicholasa,∗, T. P. Davisb, F. Federicia, J. E. Lelandc, B. S. Patela, C. Vincentd, S. H. Warda a York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD, UK b Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH c Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK d Centre for Advanced Instrumentation, Department of Physics, Durham University, Durham DH1 3LS, UK Abstract Fusion energy is often regarded as a long-term solution to the world's energy needs. However, even after solving the critical research challenges, engineer- ing and materials science will still impose significant constraints on the char- acteristics of a fusion power plant. Meanwhile, the global energy grid must transition to low-carbon sources by 2050 to prevent the worst effects of climate change. We review three factors affecting fusion's future trajectory: (1) the sig- nificant drop in the price of renewable energy, (2) the intermittency of renewable sources and implications for future energy grids, and (3) the recent proposition of intermediate-level nuclear waste as a product of fusion. Within the scenario assumed by our premises, we find that while there remains a clear motivation to develop fusion power plants, this motivation is likely weakened by the time they become available. We also conclude that most current fusion reactor designs do not take these factors into account and, to increase market penetration, fu- sion research should consider relaxed nuclear waste design criteria, raw material availability constraints and load-following designs with pulsed operation.
  • Joule Heating-Induced Particle Manipulation on a Microfluidic Chip

    Joule Heating-Induced Particle Manipulation on a Microfluidic Chip

    Joule Heating-Induced Particle Manipulation on a Microfluidic Chip Golak Kunti,a) Jayabrata Dhar,b) Anandaroop Bhattacharyaa) and Suman Chakrabortya)* a)Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal - 721302, India b)Universite de Rennes 1, CNRS, Geosciences Rennes UMR6118, Rennes, France *E-mail address of corresponding author: [email protected] We develop an electrokinetic technique that continuously manipulates colloidal particles to concentrate into patterned particulate groups in an energy efficient way, by exclusive harnessing of the intrinsic Joule heating effects. Our technique exploits the alternating current electrothermal flow phenomenon which is generated due to the interaction between non-uniform electric and thermal fields. Highly non-uniform electric field generates sharp temperature gradients by generating spatially-varying Joule heat that varies along radial direction from a concentrated point hotspot. Sharp temperature gradients induce local variation in electric properties which, in turn, generate strong electrothermal vortex. The imposed fluid flow brings the colloidal particles at the centre of the hotspot and enables particle aggregation. Further, manoeuvering structures of the Joule heating spots, different patterns of particle clustering may be formed in a low power budget, thus, opening up a new realm of on-chip particle manipulation process without necessitating highly focused laser beam which is much complicated and demands higher power budget. This technique can find its use in Lab-on-a-chip devices to manipulate particle groups, including biological cells. INTRODUCTION Manipulation and assembly of colloidal particles including biological cells are essential in colloidal crystals, biological assays, bioengineered tissues, and engineered Laboratory-on- a-chip (LOC) devices.1–6 Concentrating, sorting, patterning and transporting of microparticles possess several challenges in these devices/systems.
  • Energy and the Hydrogen Economy

    Energy and the Hydrogen Economy

    Energy and the Hydrogen Economy Ulf Bossel Fuel Cell Consultant Morgenacherstrasse 2F CH-5452 Oberrohrdorf / Switzerland +41-56-496-7292 and Baldur Eliasson ABB Switzerland Ltd. Corporate Research CH-5405 Baden-Dättwil / Switzerland Abstract Between production and use any commercial product is subject to the following processes: packaging, transportation, storage and transfer. The same is true for hydrogen in a “Hydrogen Economy”. Hydrogen has to be packaged by compression or liquefaction, it has to be transported by surface vehicles or pipelines, it has to be stored and transferred. Generated by electrolysis or chemistry, the fuel gas has to go through theses market procedures before it can be used by the customer, even if it is produced locally at filling stations. As there are no environmental or energetic advantages in producing hydrogen from natural gas or other hydrocarbons, we do not consider this option, although hydrogen can be chemically synthesized at relative low cost. In the past, hydrogen production and hydrogen use have been addressed by many, assuming that hydrogen gas is just another gaseous energy carrier and that it can be handled much like natural gas in today’s energy economy. With this study we present an analysis of the energy required to operate a pure hydrogen economy. High-grade electricity from renewable or nuclear sources is needed not only to generate hydrogen, but also for all other essential steps of a hydrogen economy. But because of the molecular structure of hydrogen, a hydrogen infrastructure is much more energy-intensive than a natural gas economy. In this study, the energy consumed by each stage is related to the energy content (higher heating value HHV) of the delivered hydrogen itself.
  • NASA Radioisotope Power Conversion Technology NRA Overview

    NASA Radioisotope Power Conversion Technology NRA Overview

    NASA Radioisotope Power Conversion Technology NRA Overview David J. Anderson NASA Glenn Research Center, 21000 Brookpark Road, Cleveland, OH 44135 216-433-8709, [email protected] Abstract. The focus of the National Aeronautics and Space Administration’s (NASA) Radioisotope Power Systems (RPS) Development program is aimed at developing nuclear power and technologies that would improve the effectiveness of space science missions. The Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) is an important mechanism through which research and technology activities are supported in the Advanced Power Conversion Research and Technology project of the Advanced Radioisotope Power Systems Development program. The purpose of the RPCT NRA is to advance the development of radioisotope power conversion technologies to provide higher efficiencies and specific powers than existing systems. These advances would enable a factor of 2 to 4 decrease in the amount of fuel and a reduction of waste heat required to generate electrical power, and thus could result in more cost effective science missions for NASA. The RPCT NRA selected advanced RPS power conversion technology research and development proposals in the following three areas: innovative RPS power conversion research, RPS power conversion technology development in a nominal 100We scale; and, milliwatt/multi-watt RPS (mWRPS) power conversion research. Ten RPCT NRA contracts were awarded in 2003 in the areas of Brayton, Stirling, thermoelectric (TE), and thermophotovoltaic (TPV) power conversion technologies. This paper will provide an overview of the RPCT NRA, a summary of the power conversion technologies approaches being pursued, and a brief digest of first year accomplishments. RADIOISOTOPE POWER CONVERSION TECHNOLOGY (RPCT) OVERVIEW The objective of the National Aeronautics and Space Administration’s (NASA) Radioisotope Power Systems (RPS) Development program is to develop nuclear power conversion technologies that would improve the effectiveness of space science missions.