Digital Commons Network^™

Uncertainty Analysis Of The Experimental Results Of Air Conditioner Performance Due To The Uncertainty Of The Equation Of State, Howard Cheung, Jérôme Frutiger, Ian Bell, Jens Abildskov, Gürkan Sin, Shengwei Wang

International Refrigeration and Air Conditioning Conference

In previous literature, the uncertainty analyses of experimental results of air conditioners usually ignored the uncertainty due to the equation of state (EoS) of the refrigerants. One possible reason was that the uncertainty reported in the EoS literature was much smaller than the one of the measurement. However, with the advancement of measurement technologies, the impact of measurement uncertainty on the air conditioner performance calculation is lowered and becomes on par with that of the EoS. Simultaneously, new research findings give more comprehensive understanding of the EoS uncertainties, such as that the uncertainty of EoS reported in previous studies was …

Analysis Of Tes With Pcm (Solid/Liquid) Integrated In A Residential System, Zidu Ma

International Refrigeration and Air Conditioning Conference

Thermal Energy Storage (TES) with Phase Change Materials (PCM) media (solid/liquid) has been investigated as an add on component to small residential systems. Simple conceptual design on the integration of TES as add-on component to typical systems has been investigated. A basic analyis with simple cycles is to be presented to answer the question whether TES integrated with existing VCC cycles could offer energy savings. In addition, the analysis is used to study the effect of subcool and/or temperature hyserisis by using the ideal Carnot Cycle. Organic PCM materials have low thermal conducitivity (0.15w/m-C to 0.20w/m-C) compared with inorganic PCMs …

Thermodynamic Design Of A Mesoscale Vapor Compression Cooling Device, Ricardo Yee, Christian Hermes

International Refrigeration and Air Conditioning Conference

This paper presents a thermodynamic methodology for designing a vapor compression refrigeration system aiming at electronics cooling. A cycle simulation model was developed firstly assuming isentropic compression and isenthalpic expansion, whereas the heat exchangers (condenser and evaporator) were modelled following a distributed approach. Whilst a 3-D heat conduction model calculates the heat leakage from the condenser to the evaporator, 2-D heat conduction models provide the temperature distribution (and the heat transfer rates) at the cold and hot ends. The fluid flow was modelled as 1-D considering both the momentum and the energy conservation equations to design the heat exchangers geometry …

Cooling Systems At Temperature Level T=28…30 K, Vitaly Bondarenko, Iurii Symonenko, Artem Chyhrin

International Refrigeration and Air Conditioning Conference

Rectification is an effective method for the Ne-He mixture separating. This method is also used at separation of neon into isotopic components (isotopes 20Ne, 21Ne and 22Ne). It is required to maintain temperatures around 28 K at the pressure of rectification column close to atmospheric pressure. This task has several solutions. Diverse cryogenic cycles, a lot of methods for removing heat and various refrigerants can be used. The simplest method of cooling the column, which is practiced in the Ne-He separation, involves the supplying the refrigerant (98 % Ne) in the top of the rectification unit. For obtaining of stable …

Performance Evaluation Of Heat Pump Cycle Using Low Gwp Refrigerant Mixtures Of Hfc-32 And Hfo-1123, Shigeru Koyama, Takahiko Miyazaki, Junki Hirayama, Nobuo Takata, Yukihiro Higashi

International Refrigeration and Air Conditioning Conference

Hydro-fluorocarbons (HFCs) have been widely used as working fluids (refrigerants) in air-conditioning and refrigeration systems. At the 1997 Kyoto Conference (COP3), a worldwide agreement was obtained to regulate the production and use of HFCs exhibit high global warming potential (GWP). In the above situation, Hydro-fluoro Olefins (HFOs) having extremely low GWP values such as HFO-1234yf, HFO-1234ze(E), HFO-1123, has attracted attentions. In this study, the performance of heat pump cycle using low GWP refrigerant mixtures of HFC-32 and HFO-1123 is evaluated experimentally. The experimental system is a water heat source vapor compression cycle, mainly composed of an inverter-controlled & hermetic-type scroll …

Review Of Shape And Topology Optimization For Design Of Air-To-Refrigerant Heat Exchangers, James Tancabel, Vikrant Chandramohan Aute, Reinhard Radermacher

International Refrigeration and Air Conditioning Conference

Air-to-refrigerant heat exchangers (HXs) have been the topic of exhaustive research as they are fundamental components of HVAC&R systems. It has been well-established that the large airside thermal resistance dominates the HX thermal resistance, and thus significant research efforts have focused on improving the air-side performance of these heat exchangers. As HXs continue to become more compact, thermal resistance reduction is typically realized through the utilization of extended secondary heat transfer surfaces such as fins. However, past research has shown that the thermal-hydraulic trade-offs provided by fins are often not attractive enough to warrant their use, especially for small diameter …

Intersection Of Art And Science Ii, Petronio Bendito, Tim Korb

Lawson Building Exhibitions on the Intersection of Art and Science

The Intersection of Art and Science exhibition is an interdisciplinary educational project that examines a wide range of expressive approaches explored by international artists working at the intersection of art, mathematics, computer science, and technology. It is a joint collaboration between the Department of Computer Science and the Patti and Rusty Rueff School of Visual and Performing Arts at Purdue University. Featured artists: Manuel Baez, Sarah Berube, Robert Bosch, Sage Jenson, Jean-Marc Castera, Marc Chamberland, Marion Chamberland, Laura De Decker, Bathsheba Grossman, Colin Liotta, Vincent J. Matsko, Kerry Mitchell, Janna Schimka, Rolf Schmuck, and Markus Schwehm. The exhibition was curated …

Don's Conference Notes, Donald T. Hawkins

Against the Grain

No abstract provided.

Void Fraction And Flow Regimes Determined By Visualization, Mass Measurement And New Capacitance Sensor, Hongliang Qian, Predrag S. Hrnjak

International Refrigeration and Air Conditioning Conference

This paper presents void fraction and flow regimes determined by three methods: visualization (high speed camera), mass measurement (quick-closing valves) and a newly developed capacitance sensor. In a way, this is a calibration process for a capacitance sensor. It is shown that new sensor can characterize flow patterns in low mass flux range and measure void fraction for horizontal and vertical tubes. A calibration procedure of void fraction measurement is based on a mass measurement (quick-closing valves). Two calibration curves for measuring void fraction in horizontal and vertical tubes are developed. With calibration curves, sensors with similar configurations can be …

Impact Of Surface Treatment And Geometrical Characteristics On The Condensate Retention And Frost Formation On Metal Foams, Kashif Nawaz, Anthony M. Jacobi, Ahmed Elatar, Brian Fricke

International Refrigeration and Air Conditioning Conference

Metal foams has been considered as promising materials for multiple thermal applications including air-cooling. Their use in such an application requires a detailed analysis of the condensate retention and frost accumulation in the metal foam pores. The current study is focused on the impact of surface treatment on the performance of metal foams when they are deployed in dehumidifying and frosting environment. Aluminum and cooper foam samples have been treated to achieve hydrophilic, hydrophobic and super hydrophobic characteristics and associated condensate retention and frost accumulation on the surface has been measured at various relative humidity and base temperature conditions. High …

Experimental Investigation Of Relative Humidity Effect On The Thermal Conductivity Of Desiccant Material, Shazia Hanif, Muhammad Sultan, Takahiko Miyazaki, Shigeru Koyama

International Refrigeration and Air Conditioning Conference

Study on effective thermal conductivity (ETC) of desiccant materials is getting attention in the literature in order to optimize the operating parameters of close and open cycle adsorption cooling systems. In addition, it is an important parameter to enhance the performance of adsorption heat pump and adsorption cooling systems (AHP/ACS). Most of the desiccant materials are porous in nature, therefore, results in different ETC at different operating conditions i.e. temperature and humidity. In order to find the more precise performance expression, the combined effect of desiccant porosity, temperature and relative humidity (RH) should be considered. In this regard, many empirical …

Tomato Cultivar Evaluation In High Tunnels, Northern Indiana, 2017, Elizabeth Maynard, Erin A. Bluhm

Purdue Fruit and Vegetable Research Reports

Tomatoes are a common crop grown in unheated greenhouses, commonly called high tunnels. Production in these structures has increased in recent years. This trial was conducted to evaluate varieties for their performance as a summer-harvested crop in soil-based high tunnel production systems. Five hybrid determinate varieties or line, one hybrid indeterminate, and one open-pollinated indeterminate variety were compared for yield, earliness, fruit size, and quality.

And They Were There- Reports Of Meetings - 37th Annual Charleston Conference, Ramue K. Kubilius, Sever Bordeianu

Against the Grain

No abstract provided.

Measuring Religiosity In A Religiously Diverse Society: The China Case, L. Luke Chao, Fenggang Yang

Department of Sociology Faculty Publications

No abstract provided.

Shaping The Religiosity Of Chinese University Students: Science Education And Political Indoctrination, Miao Li, Yun Lu, Fenggang Yang

Department of Sociology Faculty Publications

Our study examined the respective relationships between two components of higher education in mainland China—science education and political indoctrination—and the religiosity of university students. Using a cross-sectional, representative sample of about 1700 college students in Beijing, we found first that students studying natural/applied sciences were less likely to perceive Protestantism, Catholicism, and Islam as plausible and less likely to have supernatural belief, relative to students in humanities/social sciences. In addition, the more students positively evaluated the political education courses—which indicates students’ acceptance of political indoctrination—the less likely they reported Protestantism and Catholicism as being plausible. Nevertheless, neither science education nor …

Stress Analysis Of Key Components And Vibration Property Research Of The Meshing Pair In Single Screw Compressors, Chengyu Peng, Zhao Zhang, Pankang Xiong, Lei Liu, Quanke Feng, Weifeng Wu

International Compressor Engineering Conference

The single screw compressor(SSC) is widely applied to air compression, refrigeration, petrochemical industry, waste heat recovery, etc. Among SSCs, the respective strength and stiffness of the casing, screw rotor and gaterotor, where relative motions occur, play a key role on the machine running and clearance fit. Dynamic properties of the meshing pair directly affect the SSC’s vibration, as well as gaterotor’s wear-out failure. In this thesis, the strength, stiffness and dynamic characteristics of the meshing pair under different operation conditions or with components made of different materials were analyzed. Analytical method and FEM were combined to calculate and analyze the …

Film Rupture And Partial Wetting Over Flat Surfaces, Niccolo Giannetti, Piyatida Trinuruk, Seiichi Yamaguchi, Kiyoshi Saito

International Refrigeration and Air Conditioning Conference

Various technical applications require conditions which prevent thin liquid films from breaking into a series of rivulets, leaving the solid surface partly uncovered and lowering the extension of the liquid free interface. What is needed is both a criterion for the stability of the film to identify the minimum flow rate able to ensure the complete wetting of the surface and, after the film rupture, a method to estimate the wet (active) part of the same surface. At low Reynolds and high Weber numbers, the assumptions of a film with uniform thickness and complete wetting of the transfer surface cannot …

Tube-Fin Heat Exchanger Circuitry Optimization Using Integer Permutation Based Genetic Algorithm, Zhenning Li, Jiazhen Ling, Vikrant Chandramohan Aute

International Refrigeration and Air Conditioning Conference

Tube-fin heat exchangers (HXs) are widely used in air-conditioning and heat pumping applications. The performance of these heat exchangers is strongly influenced by the refrigerant circuitry, i.e. the refrigerant flow path along the different tubes in the HX core. Since for a given number of tubes, the number of possible circuitries is exponentially large, neither the exhaustive search nor traditional optimization algorithms can be used to optimize the circuitry for a given application. Researchers have previously used Genetic algorithms (GA) coupled with a learning module to solve this problem, but there is no guarantee that the resulting circuitry can be …

Void Fraction And Flow Regimes Of R134a In Horizontal And Vertical Round Tubes In Developed Adiabatic Conditions, Hongliang Qian, Predrag S. Hrnjak

International Refrigeration and Air Conditioning Conference

This paper presents flow regimes and void fraction in horizontal and vertical round tubes ID 7 mm with R134a in the adiabatic conditions and low mass flux (40-150 kg/m2s for horizontal tubes and 65-115 kg/m2s for vertical tubes) captured by a high-speed camera. Horizontal flow patterns are compared to Wojtan-Ursenbacher-Thome flow regime map and some modifications are proposed. Void fraction results for both horizontal and vertical tubes are compared to some widely used correlations. Influences of tube orientation and mass flux on void fraction are discussed. At the same vapor quality condition, void fraction of horizontal tubes is larger than …

Performance Analysis Of Internally Geared Positive Displacement Machines, Matthew Read, Nikola Stosic, Ian Smith

International Compressor Engineering Conference

Internally geared positive displacement machines consist of an externally lobed inner rotor rotating inside an internally lobed outer rotor. The rotors can have a constant profile along their length and rotate about parallel axes. Relative to the axis of rotation, the lobes of the rotors can either be straight (as found in conventional gerotor type machines), or helical (as previously proposed by the authors). In either case, the profiles must be specified in order to maintain continuous contact points between the rotors to maintain sealed working chambers. The use of stationary ported plates located at both end faces of the …

Full 3d Numerical Analysis Of A Roots Blower With Open-Source Software, Nicola Casari, Michele Pinelli, Alessio Suman, Ahmed Kovacevic, Sham Ramchandra Rane, Davide Ziviani

International Compressor Engineering Conference

In recent years, computational fluid dynamics (CFD) has been applied for the design and analysis of positive displacement machines (both compressors and expanders) for vapor compression and power generation (e.g., ORCs) applications. In particular, twin screw compressors are widely employed in industrial vapor compression systems because of their high efficiency compared to other compressor types. The numerical modeling of the operation of such machines is challenging: the dynamics of the compression (or expansion) process and the deforming working chambers make the simulation process a not-trivial task. The relative motion of the rotors and the variation of the gaps during machine …

Performance Comparison Of Empirical And Semi-Empirical Compressor Models With Uncertainty Analysis And Probabilistic Forecasting Techniques, Howard Cheung, Shengwei Wang

International Compressor Engineering Conference

There are various empirical and semi-empirical models to estimate the performance of compressors. While some studies support the use of empirical methods for their high accuracy with the available experimental observations of compressor performance, others claim that semi-empirical methods can estimate the performance at extrapolation conditions more reliably. To understand if these claims are true, quantitative comparison of various types of compressor models was conducted based on uncertainty analysis. But these methods evaluate the accuracy and uncertainty of the models separately, and it is difficult for model users to comprehend their results. In this paper, the comparison of model accuracy …

Experimental Investigation Of Aqueous Foam Based Heat Transfer In Liquid Piston Compressor For Improvement In Compression Efficiency, Vikram Patil, Pinaki Acharya, Paul Ro

International Compressor Engineering Conference

Isothermal compression results in an efficient compression due to the minimum work input associated with the isothermal process. Recently, the compression of gas using a column of high pressured liquid as a piston (also called liquid piston) has shown better performance in compression efficiency. The liquid piston can achieve a high efficiency of compression through increasing the heat transfer during gas compression by increasing the surface area to volume ratio in the compression chamber. However, to achieve highly efficient near-isothermal compression, the liquid piston needs to have significantly higher heat transfer rate during the compression. Aqueous foam can provide a …

Experimental Investigation Of A Hydrocarbon Piston Compressor For High Temperature Heat Pumps, Opeyemi Bamigbetan, Trygve Magne Tme Eikevik Prof., Petter Nekså, Michael Bantle, Christian Schlemminger, Mauro Dallai

International Compressor Engineering Conference

The global trend towards carbon neutral industries require sustainable and climate friendly heat supply. Heat pumps can meet this requirement, but the technical capability today often limit the heat supply temperature to below 90°C. The major challenge in the development of a heat pump that can deliver heat at high temperatures (115 oC) to the heat sink is the operability and performance of the compressor. The compressor electric motor cooling, lubrication stability and material durability are important physical properties to evaluate for a compressor working at high temperatures. In this study, compressors operating with natural fluids such as hydrocarbons are …

Experimental Investigation Of Water Spray Cooling For Temperature Reduction In Liquid Piston Compressor, Pinaki Acharya, Vikram Patil, Paul Ro

International Compressor Engineering Conference

The objective of this study is to analyze the effect of spray cooling in a liquid piston compressor during the compression of air in terms of temperature abatement and compression efficiency. The liquid piston can effectively cover any irregular containers making its surface area to volume ratio better than conventional reciprocating pistons. This plays an important role in increased heat transfer to the outer surface resulting in improved efficiency. As the compression process has the minimum work input during an isothermal compression, the process path needs to shift from the polytropic curve towards the isothermal curve for higher efficiency. Recently, …

Parallel Vs. Serial Noise Suppression Method For Positive Displacement (Pd) Compressors & Internal Combustion Engines (Ice), Paul Xiubao Huang Dr., Eckhard A. Groll, Sean Yonkers

International Compressor Engineering Conference

Positive displacement (PD) compressors and internal combustion engines (ICEs) are major energy consumers. For example, a typical US household may have as many as 7 compressors (2 in house AC, 2 in auto AC, 1 each for refrigerator or freezer or shop compressed air) and 4 ICEs (2 in auto, 1 each for lawn mower and auxiliary power generator). However, they both generate high amplitude pulsating pressures1 (up to 180-200 dB) and discharge flows that demand a silencer or muffler to suppress the noise but leads to high energy costs: up to 5-7% shaft power for PD compressors and up …

Optimizing Library Services — The Natural Role Of The Public Library In Emergency Management, Lindsay Wertman, Caroline J. Campbell, Michael R. Mabe, Jeffrey M. Kenton

Against the Grain

No abstract provided.

A Quick Look At Nvivo, Margaret Phillips, Jing Lu

Libraries Faculty and Staff Scholarship and Research

NVivo (QSR International, n.d.a) is software developed by QSR International for qualitative data analysis, such as content analysis and narrative analysis. The software provides a workspace for researchers to store, manage, query, and analyze unstructureddata, including text, images, audio, video, and other data types. NVivo has been used inmany library and information science studies, including to analyze interview data (Wiley& Mischo, 2016), student assignments (Insua, Lantz, & Armstrong, 2018; Phillips & Zwicky, 2017), and survey data (Gibbs, Boettcher, Hollingsworth & Slania, 2012). NVivo allows users to complete multiple qualitative analysis functions on the platform, including sorting and filtering raw data, …

Mapping Information Literacy Using The Business Research Competencies, Heather A. Howard, Nora Wood, Ilana Stonebraker

Libraries Faculty and Staff Scholarship and Research

Purpose

Librarians in higher education have adopted curriculum mapping in an effort to determine where effective information literacy instruction can help fill gaps in curriculum and prepare students both for coursework and for future research demands. While curriculum mapping has been utilized widely across academia, few studies have considered business curriculum and the development of information literacy instruction. This paper will provide an overview of the current landscape of curriculum mapping across business courses at two institutions and will provide a replicable methodology for other institutions.

Design/methodology/approach

In this paper, the authors will examine two case studies at large research …

Fred Waring And The Use Of Technology For Choral Singing, Cristopher Cayari

Library Scholars Grant Program

No abstract provided.