Mechanical Engineering Commons^™

High Temperature Heat Exchanger Project: Quarterly Progress Report July 1, 2007 Through September 30, 2007, Anthony Hechanova

Publications (NSTD)

• Ceramatec Sulfuric Acid Decomposer. The numerical model of a SiC ceramic coupon with two layers of microchannels was developed. Calculations of the factor of safety and probability of failure for the case of a straight channel were performed. Results for a pressure of 7.5 MPa were performed. The thermal and mechanical stress analyses of the Ceramatec HTHX and decomposer were completed.

• Bayonet Heat Exchanger. The thermal and mechanical stress analyses of the bayonet type HTHX and decomposer (Sandia design) were completed. Temperature profiles obtained from thermocouples measured from the Sandia experiments have been applied to the whole packed …

Unlv Research Foundation High Temperature Heat Exchanger Development: 9/08, Anthony Hechanova

Publications (NSTD)

Barriers addressed:

Nuclear Hydrogen Initiative R&D Plan – Material performance and component design and testing for the intermediate heat exchanger and high-temperature thermochemical water splitting (H₂SO₄ decomposition and HI decomposition). Improved materials for High Temperature Electrolysis.

High Temperature Heat Exchanger Project: Quarterly Progress Report April 1, 2007 Through June 30, 2007, Anthony Hechanova

Publications (NSTD)

• Ceramatec Sulfuric Acid Decomposer. Modeling with different reacting flow channel configurations (ribbed-surface channels, hexagonal channels, and diamond-shaped channels) was performed. The probability of failure for the one channel geometry with different reacting flow channel configurations was calculated to be zero in the three principal directions for all of the cases.

• Bayonet Heat Exchanger. The Matlab code for calculating the probability of failure using a two-dimensional axisymmetric model of the bayonet decomposer was developed. The probability of failure was calculated for the inner and outer SiC walls, and the intermediate quartz wall of the decomposer and found to be …

Introducing New Engineering Students To Mechanical Concepts Through An “Energy Cube” Project, Micheal O'Flaherty, Shannon Chance, Fionnuala Farrell, Christopher Montague

Conference papers

The objective of this paper is to describe a problem based learning module, called the “Energy Cube”, offered by Technological University Dublin that is designed to teach mechanical, building services and manufacturing engineering concepts to first year engineering students.

The Energy Cube project gives students hands-on experience in areas ranging from heat transfer, lighting and energy efficiency to industrial and product design. In the Energy Cube, students design and construct (using cardboard, clear plastic, and glue) a model of a building that admits as much daylight as possible while being energy efficient and aesthetically pleasing.

The students, working in teams …

High Temperature Heat Exchanger Project: Quarterly Progress Report January 1, 2007 Through March 31, 2007, Anthony Hechanova

Publications (NSTD)

• The variation of sulfur dioxide production (throughput) of the baseline design of the Ceramatec sulfuric acid decomposer with total mass flow rate of reacting flow has been calculated. According to the calculations, the sulfur dioxide production increases as the total mass flow rate of reacting flow increases regardless of the fact that decomposition percentage of sulfuric trioxide decreases. A parametric study of the baseline design of the Ceramatec sulfuric acid decomposer was performed.

• The thermal performance using various channel geometries for the decomposer was studied. The baseline design (straight channels) has 89.5% thermal efficiency while the thermal efficiency …

Thermoeconomics Of Seasonal Latent Heat Storage System, Yaşar Demirel, H. Hüseyin Öztürk

Papers in Thermal Mechanics

A simple thermoeconomic analysis is performed for a seasonal latent heat storage system for heating a greenhouse. The system consists of three units that are a set of 18 packed-bed solar air heaters, a latent heat storage tank with 6,000 kg of technical grade paraffin wax as phase-changing material, and a greenhouse of 180m2. The cost rate balance for the output of a unit is used to estimate the specific cost of exergy for a yearly operation. Based on the cost rate of exergy, fixed capital investment, operating cost, and economic data, approximate cash-flow diagrams have been prepared. The systems …

High Temperature Heat Exchanger Project: Quarterly Progress Report October 1, 2006 Through December 31, 2006, Anthony Hechanova

Publications (NSTD)

Modifications to the single-channel models of the Ceramatec heat exchanger and decomposer concept for hexagonal flow channels under two values of layer-overlapping (50% and 100%) and for diamond-shaped flow channels were completed.

The finite element calculations of the “Ball on Three Ball Test” for ceramic material for the purpose of selecting the appropriate specimen thickness for future experimental testing was performed for plate thicknesses ranging from 2 to 8 mm.

A finite element model of the “Ball on Three Ball Test” was also studied for discs having micro-channels.

Application Of H-, P- And Hp-Adaptation For Convective Heat Transfer Problems, Xiuling Wang, Darrell W. Pepper

Mechanical Engineering Faculty Research

The purpose of this paper is to describe the development and employment of an hp-adaptive finite element method (FEM) algorithm for solving heat transfer problems in partitioned enclosures, which has attracted the attention of both experimental and theoretical researchers in recent years.

Design/methodology/approach – In the hp-adaptive FEM algorithm presented here, both the element
size and the shape function order are dynamically controlled by an a posteriori error estimator based on the L2 norm; a three-step adaptation strategy is used with a projection algorithm for the flow solver.

Findings – Simulation results are obtained for 2D and 3D natural convection …

Modeling And Design Algorithms For Electromagnetic Pumps, Daniel P. Cook

Reactor Campaign (TRP)

Electromagnetic (EM) induction pumps are used in a number of nuclear energy related applications, such as circulation of molten lead-bismuth eutectic alloys in neutron targets, and circulation of liquid sodium metal in Gen IV Sodium-cooled Fast Reactors (SFR). Because EM pumps have no moving parts which can fail, they are considerably more reliable than conventional mechanical pumps for molten metal usage, and thus EM pumps are favored over mechanical pumps even though their pumping efficiency is lower and their initial cost is higher when compared to mechanical pumps of similar flow rates.

The research objectives of this task are:

• A …

Thermal Transient Flow Rate Sensor For High Temperature Liquid Metal Cooled Nuclear Reactor, Yingtao Jiang

Reactor Campaign (TRP)

In nuclear power plants and accelerator driven system (ADS) for nuclear waste treatment, it is important to monitor the coolant flow rate in the reactor core and pipe-line. In such a strong irradiation, high pressure and temperature environment, no accurate local flow measurement technique is readily available. Electromagnetic (EM) flow meter is popular in low temperature application as it is a non-intrusive technology. However, additional voltage will be produced due to temperature, flow, pressure, the chemical properties of the liquid metal and surface condition of the steel walls. In addition, the non-definite wetting behavior of liquid lead-bismuth to the electrically …

Cool Flame Propagation Speeds, Michael R. Foster, Howard Pearlman

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Cool flames are studied at reduced-gravity in a closed, unstirred, spherical reactor to minimize complexities associated with natural convection. Under such conditions, transport is controlled by diffusive fluxes and the flames are observed to propagate radially outward from the center of the reactor toward the wall. Intensified video records are obtained and analyzed to determine the flame radius as a function of time for different vessel temperatures (593–623 K) and initial pressures (55.2–81.4 kPa) using an equimolar (Ø = 5) propane-oxygen premixture. Polynomial-fits are applied to the data and differentiated to determine the cool flame propagation speeds. In nearly …