assumed that fan system performance efficiency
|
|
- Toby Arnold
- 6 years ago
- Views:
Transcription
1 This article was published in ASHRAE Journal, June Copyright 2013 ASHRAE. Posted at This article may not be copied and/or distributed electronically or in paper form without permission of ASHRAE. For more information about ASHRAE Journal, visit Standardizing Data for VFD Efficiency By Andrea Krukowski and Craig P. Wray, P.Eng., Member ASHRAE In large commercial buildings, moving air for ventilation and space-conditioning may account for 20% to 80% of HVAC site energy consumption. 1 Fan systems, which are often comprised of fans, belts, motors, and in many cases variable frequency drives (VFDs), generate the pressure rises necessary to transport the air. Even though VFDs have been used to reduce fan energy consumption by controlling fan motor speed and therefore fan airflow and pressure rise, many fan systems still use more energy than necessary, partly because the industry does not account for the impacts of fan component and system part-load efficiency variations. Fan systems seldom operate at design load, simply because this condition rarely occurs by definition and also due in part to component oversizing practices. Over roughly the past 40 years, mainstream building simulation software, as well as related codes and standards, have assumed that fan system performance efficiency is the product of individual component maximum efficiencies at design conditions, and that part-load variations of system efficiency can be described by polynomial curves that represent the various types of fan airflow control (e.g., discharge dampers, inlet vanes, and variable speed control). DOE-2, BLAST, and EnergyPlus all use the same curves, which appear to be derived from NECAP 2 and the early 1970s work of the ASHRAE Task Group on Energy Requirements for Heating and Cooling of Buildings. 3 The source of the data used to generate the curves is unknown, but may be from unpublished tests in the late 1960s or early 1970s at one manufacturer s laboratory. 4 However, these curves are not always appropriate because their default coefficients do not account for variations in component efficiency at part-load when the fan or duct system components differ from the systems that were tested (for which characteristics are unknown). Generating system specific coefficients About the Authors Andrea Krukowski is program associate at the Institute for Market Transformation in Washington, D.C. Craig P. Wray, P.Eng., is mechanical engineer, Commercial Building Systems Group, Lawrence Berkeley National Laboratory, Berkeley, Calif. 16 ASHRAE Journal ashrae.org June 2013
2 requires a priori empirical 100% knowledge of whole-system performance. 90% As a step toward correcting this deficiency, the U.S. Department of Energy (DOE) 80% 70% recently updated its Energy- Plus building simulation tool. 60% It now contains a componentbased fan system model 5 and 50% a pressure versus flow system curve model 6 40% that together explicitly describe the effects 30% of individual components on total system efficiency and 20% energy use, so that designers can more accurately predict 10% building performance and 0% size components more appropriately. Figure 1 shows an example plot of efficiency variations for a hypothetical system generated using these models. To complete these 100% improvements, databases of individual component characteristics are needed. 90% This article describes the 80% current EnergyPlus VFD efficiency component model and 70% presents performance data that 60% we collected from manufacturers in 2010 to create a VFD 50% efficiency database. At that time, there were no standards 40% for measuring VFD efficiency and, at most, manufacturers 30% provided only vague outlines of the procedures they used 20% to measure efficiency. We describe the various formats 10% manufacturers used to present their data, the variations 0% in manufacturer test procedures, and the impacts of VFD size and configuration, and show that there is a need for standardized data. We conclude by summarizing key aspects of the recent ANSI/AHRI Standard 1210, Performance Rating of Variable Frequency Drives, which provides a standardized method for measuring combined VFD and motor system efficiency. Figure 1: Efficiency versus fraction of full-load flow. A Simple VFD Efficiency Model VFD efficiency is defined as its electrical output power divided by its electrical input power. Many manufacturers and Efficiency Efficiency VFD (DOE) 4.5 Motor (High Efficiency) Belt (Medium Efficiency) 3.0 h at 40% Full-Flow (5.1 in. w.c.): Fan (BWI Airfoil) = 45.7% Combined 1.5 Pressure Rise Pressure Rise (System) Curve Fraction of Full-Load Flow Fraction of VFD Rated Output Power Full-Flow: 14,000 cfm at 15.2 in. w.c. Fan Shaft: 3,810 rpm; 62 ft lb f VFD Output: 50 hp Figure 2: VFD efficiency versus fraction of VFD rated output power (DOE). 100 hp 50 hp 10 hp 3 hp engineers assume that VFD efficiency is constant, but there are constant power losses from cooling fans and electric circuit excitations, as well as variable losses that are a product of switching and lead losses. 7 Published data about VFD efficiency at part-loads are limited. The most readily available data are provided by DOE, a sample of which is shown in Figure 2. DOE considers these efficiency values to be representative of typical pulse-width- June 2013 ASHRAE Journal Pressure Rise (in. w.c.)
3 Manufacturer Parameter VFD Rated Power Output (hp) Input Voltage (V) a b c DOE Percent of Rated VFD Output Power 3 Unknown DOE Percent of Rated VFD Output Power 5 Unknown DOE Percent of Rated VFD Output Power 10 Unknown DOE Percent of Rated VFD Output Power 20 Unknown DOE Percent of Rated VFD Output Power 30 Unknown DOE Percent of Rated VFD Output Power 50 Unknown DOE Percent of Rated VFD Output Power 60 Unknown DOE Percent of Rated VFD Output Power 75 Unknown DOE Percent of Rated VFD Output Power 100 Unknown DOE Percent of Rated VFD Output Power 200 to 400 Unknown A Percent of Full Speed 50 Unknown B Percent of Full Speed B Percent of Full Speed B Percent of Full Speed B Percent of Full Speed C Percent of Rated VFD Output Power C Percent of Rated VFD Output Power Table 1: Coefficients for selected models for Equation 1. modulated VFDs, but also states that there is no widely accepted protocol that allows for efficiency comparisons between different drive models or brands. In addition, there are many ways to set up a VFD that can affect the operating efficiency. 8 The DOE VFD efficiency data can be represented using the following relationship: η VFD = a X b+ X VFD VFD + c X where η VFD represents VFD efficiency; a, b, and c denote coefficients determined from the performance characteristics of a particular drive; and X VFD is the ratio of VFD output power at the operating point to maximum VFD output power. 5 Table 1 provides model coefficients that can be used to reproduce the published DOE curves. VFD Efficiency Data from Manufacturers To determine if the relationship described by Equation 1 could be applied to predict the energy performance of all VFDs used for HVAC applications, we collected performance data directly from manufacturers. We contacted 22 manufacturers, but only five manufacturers, identified as Manufacturers A through E, could provide part-load data and even some of these data were too limited to be of use. In the end, 44 models from Manufacturers A, B, and C, along with the DOE data, were analyzed. The drives were rated between 1 hp (0.8 kw) and 200 hp (149 kw) and were all deemed appropriate for use in HVAC applications in large commercial buildings. Manufacturers A and B provided three-dimensional data: VFD efficiency as a function of both the fraction of full-load VFD (1) torque and fraction of full speed (ω/ω max ). For these data, to develop an efficiency curve as a function of fractional speed, the relation between load and speed needed to be determined. HVAC systems are variable torque applications (as opposed to constant torque applications) of VFDs. 9 Theoretically, the motor torque required increases with the square of its speed; conversely, speed increases as the square root of the torque. Therefore, one can select a fractional speed that corresponds to each fractional torque to define a locus of points that forms the variable torque curve as a function of fractional speed. In the cases of the 25%, 50%, 75%, and 100% constant torque efficiency curves provided by the manufacturers as a function of fractional speed, the corresponding fractional speeds, respectively, are 50%, 71%, 87%, and 100%. Equation 1 was then used, but with X VFD = ω/ω max. Manufacturer C provided power loss data for each VFD (i.e., power dissipated as heat) when it is operated at its rated current and indicated that this loss could be scaled as a function of fractional motor load using a single curve that it provided for all drives. Because output current was the rating baseline, we assumed that motor load in this case is the load on the VFD and thus is the fractional output power of the VFD. Efficiency as a function of VFD fractional output power (similar parameter space to the DOE data) was calculated using Equation 2: HVFD, output η VFD = = HVFD, input HVFD, input W f ( HVFD, output / H,, H VFD, input VFD output max where H represents power, W refers to power lost at rated ) (2) 18 ASHRAE Journal ashrae.org June 2013
4 current, and f is the manufacturer-provided part-load modifier function of fractional VFD output power. Comparing Model With Data Assuming that the relationship between η VFD and X VFD would be of the form described by Equation 1, coefficients for each VFD were determined by minimizing the root mean square (RMS) difference between the efficiencies predicted by the model and the efficiencies supplied by the manufacturers. Coefficients for selected models are listed in Table 1. An uncertainty analysis was then used to confirm the validity of the model. The absolute value and RMS errors determined during the uncertainty analysis were used to confirm how accurately the model could reproduce manufacturer s data. Figure 3 shows examples of the datasets analyzed for 50 hp (37 kw) drives and the curves generated by the model as either a function of the fraction of full speed or fraction of full-load VFD output power, depending on what data were provided by each manufacturer. As can be seen in Figure 3, the manufacturers data align well with the curves generated by the model. More specifically, Figure 4 shows the RMS errors in predicting manufacturer s efficiency for each VFD analyzed. The average RMS error was 0.25% while the maximum RMS error was 0.90% (range of 1 to 600 hp (0.8 to 448 kw). The average maximum difference between fitted and manufacturer efficiencies was 0.54%. The low RMS errors demonstrate that Equation 1 is a suitable model for the data provided by the manufacturers. Efficiency 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% DOE (Percent Load), 50 hp Manufacturer A (Percent Speed) Manufacturer B (Percent Speed), Series 1, 50 hp at 480 V Manufacturer B (Percent Speed), Series 2, 50 hp at 480 V Manufacturer B (Percent Speed), Series 1, 50 hp at 240 V Manufacturer B (Percent Speed), Series 2, 50 hp at 240 V Manufacturer C (Percent Load), 50 hp at 480 V Manufacturer C (Percent Load), 50 hp at 240 V 0% Fraction of Rated VFD Output Power (Load) or Full Speed Figure 3: Fitted efficiency curves & manufacturers data for models analyzed rated 50 hp (37 kw). RMS Error (%) that manufacturers used to measure efficiency could be obtained. Specifically, Manufacturers A and C could not verify how their provided efficiency values were determined. Manufacturer B acknowledged that the full-load efficiencies of its VFD models and the provided relationship between efficiency and partload conditions were derived theoretically based on compiling the sources of losses, which may account for why the model s errors for predicting Manufacturer B s efficiencies were so low. Factors that impact losses that they reportedly considered in Variations in Manufacturer Test Procedures When we obtained the performance characteristics in 2010, there were no standards for measuring VFD efficiency and, at most, only vague outlines of procedures DOE A B C hp hp hp hp Percent Speed Figure 4: RMS error in predicted efficiency for each model. 20 ASHRAE Journal ashrae.org June 2013
5 their calculations include the actual line voltage, actual output current, actual site temperature, motor cable length and type, carrier frequency, component tolerance, and losses within the controller and rectifier sections. The efficiencies were calculated by assuming a fixed value for all of these factors. The manufacturer stated that actual heat losses can vary by ±15% from these calculated values. Manufacturer B asserted that the efficiencies were not physically measured because available methods were not reliable or not accessible due to prohibitive costs. Available test procedure outlines were only described anecdotally by the manufacturers. One popular method of measuring energy loss is to place the VFD in an enclosure and measure the change in temperature or heat loss using an infrared heat gun or calorimeter, respectively; in this procedure, it is assumed that all losses in the drive are transformed into heat that is dissipated into the enclosure. Efficiency is calculated using Equation 2. A more direct method of calculating efficiency is to use power meters to obtain input and output power readings. However, this approach is subject to the limits of instrumentation error. Moreover, some power meters may not give accurate readings due to harmonics generated by VFDs, so only power meters with a broad frequency range and suitable filters should be selected. Manufacturers D and F, neither of which provided usable part-load data, stated that a combination of these two methods was used to calculate efficiency. Even with these sketches of procedures, no manufacturer could describe the instruments used, how the equipment was calibrated, calculation methods, and corresponding uncertainties. The lack of a verified and standardized procedure makes a direct comparison of the obtained datasets less useful and may account for a lack of consistency in trends in the datasets, which are described below. Effects of VFD Size and Configuration Most VFDs had maximum efficiencies of approximately 95% to 98% and the efficiency decreased as the fraction of motor load or speed decreased. For most drives, the drive efficiencies peaked at approximately the nominal rating, but for Manufacturer C, efficiencies peaked at approximately 60% part load. Some data demonstrated how efficiency changes with horsepower rating. For example, the DOE data in Figure 2 represent efficiency as a function of the VFD rated output power and show a marked difference in the efficiencies between the larger and smaller drives, with larger drives tending to be more efficient. The difference is not as pronounced for nominal power ratings of approximately 20 hp (15 kw) and above. Performance characteristics for drives from Manufacturers B and C in Figure 3 show similar trends. Manufacturer B stated that parts of the drives are not optimized for size, so efficiency depends on the rated horsepower, but only three different efficiency curves for models ranging from a nominal power rating of 1.5 hp (1.1 kw) to 125 hp (93 Advertisement formerly in this space. 22 ASHRAE Journal June 2013
6 kw) were produced. For datasets that provided efficiency as a function of the rated power, the smallest model of a series generally has the worst efficiency; however, the largest models are not necessarily the most efficient. Manufacturer A stated that the efficiencies of its drives are independent of the nominal power rating and did not provide efficiencies as a function of horsepower. Previous studies have demonstrated that changing drive settings and other factors affect VFD efficiency, but the effect of these factors is undocumented in the obtained datasets. For example, Gao, et al. 10 and ASHRAE 11 each show that drives are more efficient at lower carrier frequencies, although they are often run at higher frequencies to minimize background noise. Although this fact is stated in data summaries of all manufacturers, as well as by DOE, it is not quantitatively described by any manufacturer. Data provided by Manufacturers B and C are also a function of the input voltage supply: as shown in Figures 3 and 5, the data demonstrate that VFDs are more efficient at 480 V than 240 V. However, the other datasets did not show how input voltage affects efficiency. The motor connection also has an effect on VFD efficiency. Manufacturer B stated that increasing the long motor lead length would decrease drive efficiency, but this amount was not quantified nor was long length defined. Since procedures were not available, it is unknown whether the VFDs tested were connected to motors and how the connection affects VFD efficiency, another caveat to the performed analysis. Therefore, though previous research shows that VFD efficiency is affected by many different variables, including carrier frequency, rated horsepower, input voltage, and motor connection, these factors are not properly documented nor accounted for in available data. Therefore, the effect of each of these factors on VFD efficiency cannot be precisely described, but should be incorporated into standardized tests and performance reporting. For a complete representation of VFD performance, a VFD should be characterized by a family of efficiency curves as a function of both fractional torque and speed, 12 which was only provided by Manufacturers A and B. Ideally, performance would be evaluated by testing multiple load and speed combinations based on typical variable torque loads, 13 using a range of VFD configurations that are most commonly applied. A Need for Standardized Data The curves shown in Figure 3 are in two different parameter spaces, depending on what data were provided. While one might be inclined to simply attribute the differences in performance between manufacturers to differences in quality, the variations between curves in the different parameter spaces Advertisement formerly in this space. June 2013 ASHRAE Journal 23
7 cannot be directly compared. The use of different parameter spaces reinforces the need for a standardized and known procedure and format. Without these, any comparisons or observed trends must be treated with caution. As an example to show how the curves in Figure 3 could be compared in a homogeneous parameter space more common to a system designer, we used the hypothetical system and efficiency curves shown in Figure 1 and the EnergyPlus models to translate the curves so that they are all expressed in terms of fraction of full-load airflow, as shown in Figure 5. The curves in Figure 1 represent a commercially available 18 in. (0.46 m) diameter double-width double-inlet backward-inclined airfoil centrifugal supply fan with a 14,000 cfm (6.7 m 3 /s) design flow at 15.2 in. w.c. (3780 Pa), which corresponds to a speed of 3,810 rpm at a torque of 62 ft lb f (84 N-m); a medium efficiency V-belt; a high efficiency motor; a VFD with 50 hp (37 kw) rated output; and a variable air volume (VAV) supply air distribution system with coil and filter elements and a duct static pressure setpoint of 1 in. w.c. (249 Pa). In SI units, the system curve that we used has the form: 2 p = Q Q (3) where Δp is the fan pressure rise (Pa) and Q is the fan airflow (m 3 /s). In Figure 1, maximum efficiencies for the fan, belt, motor, and VFD, respectively, are about 75%, 96%, 94%, and 97%. The fan system efficiency at full-flow is about 65%. Part-load efficiencies and speeds for the fan were derived from the manufacturer s performance map (using dimensionless relationships described in the EnergyPlus fan component model 5 ). Part-load efficiencies for the belts, motor, and VFD, respectively, were derived from efficiency data for V-belts provided by AMCA 14 and Nadel et al., 9 from DOE MotorMaster+ 15 data, and from the various 50 hp (37 kw) VFD efficiency curves being translated. For the system in Figure 1, at 40% of full-flow (near where the system curve crosses the fan s do not select curve), the partload system efficiency is much lower: about 46%. In Figure 5, it appears that the DOE curve may be a good mid-range estimate based on the data we present for a 50 hp (37 kw) drive. However, this is only coincidence because the Manufacturer B data represent large ranges of drive output powers, Manufacturer C assumes that all of its drives perform at part load as shown, and one can see that the DOE efficiencies decrease as drive output decreases. For example, if one uses the coefficients in Table 1 for a DOE 3 hp (2.2 kw) VFD, it would roughly generate the Manufacturer C curve. Conversely, if one used the coefficients in Table 1 for a DOE 200 to 400 hp VFD, it would roughly generate the lower range of the Manufacturer B curves. These variations again reinforce the need for standardized data. For now, until better data become available, Equation 1 and the data in Table 1 can be used to estimate the range of installed performance that can be expected. A Step Toward Standardized Ratings In December 2011, AHRI published ANSI/AHRI Standard 1210, Performance Rating of Variable Frequency Drives, which specifies methods for measuring the performance of VFDs used for HVAC applications. 16 Drives evaluated according to the standard will have published ratings for drive system efficiency, motor insulation stress, and power line harmonics. The standard stipulates voltages that VFDs should be tested at, as well as power source. It also specifies various speed and load testing points at which the VFD needs to be evaluated. Standard 1210 requires that the VFD be connected to a motor during the performance tests and describes the allowable motor connections. The reported drive system efficiency is the ratio of motor mechanical output power divided by VFD electrical input power. The standard does not separate out VFD efficiency. Previous research has established that the motor efficiency may 24 ASHRAE Journal June 2013
8 change when connected to a 100% VFD compared to a simple line connection, which may be partially attributed to the previously described harmonics that VFDs can gener- 90% ate. Harmonics can increase motor losses, reduce torque, 80% cause overheating, and produce torque pulsation. Manufacturer G, which did not have part-load efficiency data, 70% noted that an increase in VFD efficiency may decrease motor efficiency, but other manufacturers did not mention this 60% potential effect. As a result, to use the 1210 test results during system design, one needs 50% to know whether the intended combination of VFD and motor matches the 1210 test configuration. The publishing of Standard 1210 is a crucial step in completing a database of VFD performance characteristics and a better understanding of how combined VFD and motor efficiency affects fan system operation. When manufacturers produce efficiency data according to this standard and complete and consistent data in the form of a three-dimensional performance map are available, methods should be developed to separate out the VFD and motor efficiencies and, the drives analyzed in this project should be reevaluated to verify whether Equation 1 still holds, or this equation should be reformulated to represent VFD and motor packages. Furthermore, the database should be plotted in dimensionless Efficiency DOE Manufacturer A Manufacturer B, 480 V, Series 1 Manufacturer B, 480 V, Series 2 Manufacturer B, 240 V, Series 1 Manufacturer B, 240 V, Series 2 Manufacturer C, 480 V Manufacturer C, 240 V Full-Flow: 14,000 cfm at 15.2 in. w.c. Fan Shaft: 3,810 rpm; 62 ft lb f ; VFD Output: 50 hp Fraction of Full-Load Flow Figure 5: VFD efficiency for models rated 50 hp (37 kw) versus fraction of full-load flow. space and plotted as a function of the flow rate of the fan system to better understand how part-load performance varies with fan operation. With these new modeling techniques and standardized data, designers and end users will be able to better understand building energy performance and use this information to help size equipment, which will improve building energy efficiency. References ASHRAE Handbook HVAC Systems and Equipment, Chapter 19, p Henninger, R.H. (ed) NECAP NASA s Energy-Cost Analysis Program, Part II Engineering Manual. National Aero- June 2013 ASHRAE Journal 25
9 Advertisement formerly in this space. nautics and Space Administration Contractor Report prepared by General American Transportation Corporation, Nites, Ill. September. NASA CR-2590 Part II. 3. Stoecker, W.F Energy Calculations 2: Procedures for Simulating the Performance of Components and Systems for Energy Calculations ASHRAE Task Group on Energy Requirements for Heating and Cooling of Buildings. 4. Personal communication between Craig Wray and Doug Hittle, University of Colorado, Wray, C.P EnergyPlus Engineering Reference: Component Fan Model, Board of Trustees of the University of Illinois and Regents of the University of California through the Ernest Orlando Lawrence Berkeley National Laboratory, October. pp Sherman, M.H. and C.P. Wray Parametric System Curves: Correlations between Fan Pressure Rise and Flow for Large Commercial Buildings. Lawrence Berkeley National Laboratory Report. LBNL-3542E. 7. Piesciorovsky, E.C., W.N. White Heat gain from adjustable speed (variable frequency) drives. ASHRAE Transactions 116(2). 8. DOE Motor Tip Sheet #11: Adjustable Speed Drive Part-Load Efficiency. U.S. Department of Energy Industrial Technologies Program Nadel, S., et al Energy-Efficient Motors: A Handbook on Technology, Program, and Policy Opportunities, 2nd edition. Chapter 4: Motor Control Technologies. pp Washington, D.C.: American Council for an Energy Efficient Economy. 10. Gao, X., S. McInerny, S. Kavanaugh Efficiencies of an 11.2 kw variable speed motor and drive. ASHRAE Transactions 107(2) ASHRAE Handbook HVAC Systems and Equipment, Chapter Domijan, Jr., A., A. Abu-aisheh, D. Czarkowski Efficiency and separation of losses of an induction motor and its adjustablespeed drive at different loading/speed combinations. ASHRAE Transactions 3(1): Almeida, A., P. Angers, C. Brunner, M. Doppelbauer Motors with adjustable speed drives: testing protocol and efficiency standard. Proceedings of the 6th International Conference eemods 09: Energy Efficiency in Motor Driven Systems. 14. AMCA Field Performance Measurement of Fan Systems, Publication Appendix L. Arlington, Heights, Ill.: Air Movement and Control Association, Inc. 15. DOE MotorMaster+ Version Developed for the U.S. Department of Energy by the Washington State University Cooperative Extension Energy Program. September AHRI ANSI/AHRI Standard , Performance Rating of Variable Frequency Drives ASHRAE Journal June 2013
INVITATION TO SUBMIT A RESEARCH PROPOSAL ON AN ASHRAE RESEARCH PROJECT TRP, Experimental Evaluation of the Efficiency of Belt Drives for Fans
INVITATION TO SUBMIT A RESEARCH PROPOSAL ON AN ASHRAE RESEARCH PROJECT 1769-TRP, Experimental Evaluation of the Efficiency of Belt Drives for Fans Attached is a Request-for-Proposal (RFP) for a project
More informationINVITATION TO SUBMIT A RESEARCH PROPOSAL ON AN ASHRAE RESEARCH PROJECT TRP, Experimental Evaluation of the Efficiency of Belt Drives for Fans
INVITATION TO SUBMIT A RESEARCH PROPOSAL ON AN ASHRAE RESEARCH PROJECT 1769-TRP, Experimental Evaluation of the Efficiency of Belt Drives for Fans Attached is a Request-for-Proposal (RFP) for a project
More informationHydraulic Drive Head Performance Curves For Prediction of Helical Pile Capacity
Hydraulic Drive Head Performance Curves For Prediction of Helical Pile Capacity Don Deardorff, P.E. Senior Application Engineer Abstract Helical piles often rely on the final installation torque for ultimate
More informationPerformance of VAV Parallel Fan-Powered Terminal Units: Experimental Results and Models
NY-08-013 (RP-1292) Performance of VAV Parallel Fan-Powered Terminal Units: Experimental Results and Models James C. Furr Dennis L. O Neal, PhD, PE Michael A. Davis Fellow ASHRAE John A. Bryant, PhD, PE
More informationDevelopment of Power-head Based Fan Airflow Station
ESL-IC-5-1- Development of Power-head Based Fan Airflow Station Gang ang Research associate University of Nebraska, Lincoln Mingsheng Liu Professor University of Nebraska, Lincoln Abstract Fan airflow
More informationComponents of Hydronic Systems
Valve and Actuator Manual 977 Hydronic System Basics Section Engineering Bulletin H111 Issue Date 0789 Components of Hydronic Systems The performance of a hydronic system depends upon many factors. Because
More informationCentral Station Air-Handling Units
2008 STANDARD FOR Standard 430 Central Station Air-Handling Units ISHRAE ( INDIAN SOCIETY OF HEATING, REFRIGERATING & AIR CONDITIONING ENGINEERS 4100 N. FAIRFAX DR., STE. 200 ARLINGTON, VIRGINIA 22203
More informationFan Efficiency Grades and System Effect and Their Effects on HVAC Systems
Fan Efficiency Grades and System Effect and Their Effects on HVAC Systems Matt Spink, P.E. Greenheck Fan Corporation Learning Objectives Understanding Fan Efficiency Grades (FEG) Selection of fans within
More informationMachine Drive Electricity Use in the Industrial Sector
Machine Drive Electricity Use in the Industrial Sector Brian Unruh, Energy Information Administration ABSTRACT It has been estimated that more than 60 percent of the electricity consumed in the United
More informationFan Powered Terminal Units FPV, FDV Series Variable Volume Parallel Flow
Recommended Air Volume Ranges CP 101 Unit Size L/s Min.* L/s Max. cfm Min.* cfm Max. 6 31 212 66 450 8 62 378 132 800 10 104 637 221 1350 12 146 991 310 2100 14 207 1416 439 3000 16 268 1888 568 4000 CP
More informationOperating Efficiency of Crankshaft Drive Pumps
By Dr. Scott Veenhuizen, OMAX Corporation Operating Efficiency of Crankshaft Drive Pumps Nozzle output power, electrical input power, and pump crankshaft input power of a 380 MPa variable speed crankshaft
More informationInfluence of Cylinder Bore Volume on Pressure Pulsations in a Hermetic Reciprocating Compressor
Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 2014 Influence of Cylinder Bore Volume on Pressure Pulsations in a Hermetic Reciprocating
More informationTime-Dependent Behavior of Structural Bolt Assemblies with TurnaSure Direct Tension Indicators and Assemblies with Only Washers
Time-Dependent Behavior of Structural Bolt Assemblies with TurnaSure Direct Tension Indicators and Assemblies with Only Washers A Report Prepared for TurnaSure, LLC Douglas B. Cleary, Ph.D., P.E. William
More informationComparing FEM Transfer Matrix Simulated Compressor Plenum Pressure Pulsations to Measured Pressure Pulsations and to CFD Results
Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 2012 Comparing FEM Transfer Matrix Simulated Compressor Plenum Pressure Pulsations to Measured
More informationAcceleration Behavior of Drivers in a Platoon
University of Iowa Iowa Research Online Driving Assessment Conference 2001 Driving Assessment Conference Aug 1th, :00 AM Acceleration Behavior of Drivers in a Platoon Ghulam H. Bham University of Illinois
More informationCommissioning chilled water TES systems
Commissioning chilled water TES systems Chilled water thermal energy storage systems should be as simple as possible. The success of a project depends on documenting and continually evaluating the owner
More informationVAV AIRFLOW CONTROL. Reliable Without Limitations? Ron Simens, Facility Dynamics Engineering. 21 st National Conference on Building Commissioning
Reliable Without Limitations? Ron Simens, Facility Dynamics Engineering 21 st National Conference on Building Commissioning AIA Quality Assurance The Building Commissioning Association is a Registered
More informationANSI/AHRI Standard 880 (I-P) 2011 Standard for Performance Rating of Air Terminals
ANSI/AHRI Standard 880 (I-P) 2011 Standard for Performance Rating of Air Terminals Approved by ANSI on 27 October 2011 IMPORTANT SAFETY DISCLAIMER AHRI does not set safety standards and does not certify
More informationMERV Filter Models for Aerobiological Applications. W.J. Kowalski, PE, PhD W.P. Bahnfleth, PE, PhD The Pennsylvania State University
MERV Filter Models for Aerobiological Applications W.J. Kowalski, PE, PhD W.P. Bahnfleth, PE, PhD The Pennsylvania State University Recent concerns about bioterrorism and existing concerns about indoor
More informationASTM D4169 Truck Profile Update Rationale Revision Date: September 22, 2016
Over the past 10 to 15 years, many truck measurement studies have been performed characterizing various over the road environment(s) and much of the truck measurement data is available in the public domain.
More informationProduct Data. Features/Benefits. 35K Bypass Terminal. 110 to 4400 cfm
Product Data 35K Bypass Terminal 110 to 4400 cfm Carrier s 35K Series bypass terminals offer: 20-gage, galvanized steel casing construction 1/2-in. thick, dual density fiberglass insulation meeting NFPA
More informationMotor Systems Tool (MST)
FACT SHEET No. 28 Motor Systems Tool (MST) The five key aspects of system optimisation 1. Adapting the system correctly to the demand 2. Optimising the running hours 3. Using modern, efficient components
More informationGT-Suite Users Conference
GT-Suite Users Conference Thomas Steidten VKA RWTH Aachen Dr. Philip Adomeit, Bernd Kircher, Stefan Wedowski FEV Motorentechnik GmbH Frankfurt a. M., October 2005 1 Content 2 Introduction Criterion for
More informationOptimization of Seat Displacement and Settling Time of Quarter Car Model Vehicle Dynamic System Subjected to Speed Bump
Research Article International Journal of Current Engineering and Technology E-ISSN 2277 4106, P-ISSN 2347-5161 2014 INPRESSCO, All Rights Reserved Available at http://inpressco.com/category/ijcet Optimization
More informationLow Rigor ISP Study Summary Fan Coil Unit EC Motors
Low Rigor ISP Study Summary Fan Coil Unit EC Motors ISP Study Target Application: Fan Coil Unit Motors for Systems Designed from 2012 through 2014 ISP Report Finalization Date: 08/03/2017 1 RESEARCH SUMMARY
More informationANSI/AHRI Standard 881 (SI) with Addendum Standard for Performance Rating of Air Terminals
ANSI/AHRI Standard 881 (SI) with Addendum 1 2011 Standard for Performance Rating of Air Terminals Approved by ANSI on October 27, 2011 WITH ADDENDUM 1, PERFORMANCE RATING OF AIR TERMILS June 2012 Note:
More information44 (0) E:
FluidFlow Equipment Sizing Handbook Flite Software 2018 Flite Software N.I. Ltd, Block E, Balliniska Business Park, Springtown Rd, Derry, BT48 0LY, N. Ireland. T: 44 (0) 2871 279227 E: sales@fluidflowinfo.com
More informationPerformance of VAV Fan-Powered Terminal Units: Experimental Setup and Methodology
NY-08-012 (RP-1292) Performance of VAV Fan-Powered Terminal Units: Experimental Setup and Methodology James C. Furr Dennis L. O Neal, PhD, PE Michael A. Davis Fellow ASHRAE John A. Bryant, PhD, PE Andrew
More informationFan Efficiency Metrics
EEDAL 2017 University of California, Irvine September 14, 2017 Fan Efficiency Metrics Michael Ivanovich, Senior Director, Industry Relations, Air Movement and Control Association Mike Wolf, Greenheck Fan
More informationPower Quality Luis Vargas Research Engineer 9/18/2008
Page: 1 of 5 Luis Vargas Research Engineer 9/18/2008 Page: 2 of 5 As we make advances on green technology, we get a better understanding of the efficiencies and deficiencies on how we consume electricity.
More informationPerformance of Batteries in Grid Connected Energy Storage Systems. June 2018
Performance of Batteries in Grid Connected Energy Storage Systems June 2018 PERFORMANCE OF BATTERIES IN GRID CONNECTED ENERGY STORAGE SYSTEMS Authors Laurie Florence, Principal Engineer, UL LLC Northbrook,
More informationYou have probably noticed that there are several camps
Pump Ed 101 Joe Evans, Ph.D. Comparing Energy Consumption: To VFD or Not to VFD You have probably noticed that there are several camps out there when it comes to centrifugal pump applications involving
More informationDemand Based Static Pressure Reset Control for Laboratories
Accutrol, LLC Product Sheet Demand Based Static Pressure Reset Control for Laboratories Accutrol, LLC 21 Commerce Drive, Danbury, CT 06810 203-445-9991 www.accutrolllc.com Contents and specifications are
More informationLarge Electric Motor Reliability: What Did the Studies Really Say? Howard W Penrose, Ph.D., CMRP President, MotorDoc LLC
Large Electric Motor Reliability: What Did the Studies Really Say? Howard W Penrose, Ph.D., CMRP President, MotorDoc LLC One of the most frequently quoted studies related to electric motor reliability
More informationAMCA International s Opening Session
AMCA International s Opening Session AMCA International 59 th Annual Meeting Redux Opening Session Geoff Sheard 2013-14 AMCA President Call to Order What to Expect AMCA Air System Industry Update Moderator
More informationDevelopment of Large-capacity Indirect Hydrogen-cooled Turbine Generator and Latest Technologies Applied to After Sales Service
Development of Large-capacity Indirect Hydrogen-cooled Turbine Generator and Latest Technologies Applied to After Sales Service 39 KAZUHIKO TAKAHASHI *1 MITSURU ONODA *1 KIYOTERU TANAKA *2 SEIJIRO MURAMATSU,
More informationDevelopment of a High Efficiency Induction Motor and the Estimation of Energy Conservation Effect
PAPER Development of a High Efficiency Induction Motor and the Estimation of Energy Conservation Effect Minoru KONDO Drive Systems Laboratory, Minoru MIYABE Formerly Drive Systems Laboratory, Vehicle Control
More informationIntroduction: Supplied to 360 Test Labs... Battery packs as follows:
2007 Introduction: 360 Test Labs has been retained to measure the lifetime of four different types of battery packs when connected to a typical LCD Point-Of-Purchase display (e.g., 5.5 with cycling LED
More informationINTERNATIONAL JOURNAL OF APPLIED ENGINEERING RESEARCH, DINDIGUL Volume 1, No 4, 2011
Numerical modal analysis of Howell Bunger valve using FEM method Farid Vakili Tahami, Mohammad Zehsaz, Mohammad Ali Saeimi Sadigh, Amin Paykani Department of Mechanical Engineering, University of Tabriz,
More informationM2010 Time Line and Test Issues EBB, October 10, 2007
The M2010 Standard is now in its final form. There may be some editorial changes in the text before it is published in booklet form but the testing and other requirements will not be affected. This standard
More informationControl Valves & Coil Packs
ENGINEER S NOTEBOOK This article was published in ASHRAE Journal, April 2013. Copyright 2013 ASHRAE. Posted at www.ashrae.org. This article may not be copied and/or distributed electronically or in paper
More informationStructural Analysis Of Reciprocating Compressor Manifold
Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 2016 Structural Analysis Of Reciprocating Compressor Manifold Marcos Giovani Dropa Bortoli
More informationIMPROVING MOTOR SYSTEM EFFICIENCY WITH HIGH EFFICIENCY BELT DRIVE SYSTEMS
IMPROVING MOTOR SYSTEM EFFICIENCY WITH HIGH EFFICIENCY BELT DRIVE SYSTEMS Contents Introduction Where to Find Energy Saving Opportunities Power Transmission System Efficiency Enhancing Motor System Performance
More informationPROCESS VFD SAVINGS CALCULATOR USER GUIDE CONTENTS ENERGY EFFICIENCY FOR BUSINESS CUSTOM INCENTIVES CUSTOM-TO-GO
PROCESS VFD SAVINGS CALCULATOR USER GUIDE ENERGY EFFICIENCY FOR BUSINESS CUSTOM INCENTIVES CUSTOM-TO-GO CONTENTS 1. Getting Started... 2 2. Measure Tool Description... 2 2.1. Applicable Types of Equipment
More informationPerformance Rating of Central Station Air-handling Unit Supply Fans
AHRI Standard 430 (I-P) With Addendum 1 2014 Standard for Performance Rating of Central Station Air-handling Unit Supply Fans AHRI STANDARD 430 (I-P)-2014 WITH ADDENDUM 1, PERFORMANCE RATING OF CENTRAL
More informationBiennial Assessment of the Fifth Power Plan
Biennial Assessment of the Fifth Power Plan Gas Turbine Power Plant Planning Assumptions October 17, 2006 Simple- and combined-cycle gas turbine power plants fuelled by natural gas are among the bulk power
More informationA Review of DC/DC Converter De-rating Practices
A Review of DC/DC Converter De-rating Practices By: Tim Powers As a power design engineer, the most commonly asked questions are by far related to thermal performance of dc-dc converters. At issue are
More informationENERGY ANALYSIS OF A POWERTRAIN AND CHASSIS INTEGRATED SIMULATION ON A MILITARY DUTY CYCLE
U.S. ARMY TANK AUTOMOTIVE RESEARCH, DEVELOPMENT AND ENGINEERING CENTER ENERGY ANALYSIS OF A POWERTRAIN AND CHASSIS INTEGRATED SIMULATION ON A MILITARY DUTY CYCLE GT Suite User s Conference: 9 November
More informationLaboratory Exhaust Systems
Laboratory Exhaust Systems Vektor -HS, Vektor -MS and Vektor -CS with Variable Geometry Nozzle September 017 Vektor -HS, Vektor -MS and Vektor -CS Greenheck s Variable Geometry Nozzle exhaust systems allow
More informationSimulation of Performance Parameters of Spark Ignition Engine for Various Ignition Timings
Research Article International Journal of Current Engineering and Technology ISSN 2277-4106 2013 INPRESSCO. All Rights Reserved. Available at http://inpressco.com/category/ijcet Simulation of Performance
More informationDamping Ratio Estimation of an Existing 8-story Building Considering Soil-Structure Interaction Using Strong Motion Observation Data.
Damping Ratio Estimation of an Existing -story Building Considering Soil-Structure Interaction Using Strong Motion Observation Data by Koichi Morita ABSTRACT In this study, damping ratio of an exiting
More informationHigh Speed Reciprocating Compressors The Importance of Interactive Modeling
High Speed Reciprocating Compressors The Importance of Interactive Modeling Christine M. Gehri Ralph E. Harris, Ph.D. Southwest Research Institute ABSTRACT Cost-effective, reliable operation of reciprocating
More informationLong-Term Costs and Savings of Properly Rewound Motors
Long-Term Costs and Savings of Properly Rewound Motors Erin Hope, Bonneville Power Administration Dennis Bowns, Green Motors Practices Group ABSTRACT Industrial facilities send thousands of motors to motor
More informationModeling Filter Bypass: Impact on Filter Efficiency
Modeling Filter Bypass: Impact on Filter Efficiency Matthew Ward Jeffrey Siegel, Ph.D. Member ASHRAE ABSTRACT Current models and test methods for determining filter efficiency ignore filter bypass, the
More informationAdvanced Battery Models From Test Data For Specific Satellite EPS Applications
4th International Energy Conversion Engineering Conference and Exhibit (IECEC) 26-29 June 2006, San Diego, California AIAA 2006-4077 Advanced Battery Models From Test Data For Specific Satellite EPS Applications
More informationSTEALTH INTERNATIONAL INC. DESIGN REPORT #1001 IBC ENERGY DISSIPATING VALVE FLOW TESTING OF 12 VALVE
STEALTH INTERNATIONAL INC. DESIGN REPORT #1001 IBC ENERGY DISSIPATING VALVE FLOW TESTING OF 12 VALVE 2 This report will discuss the results obtained from flow testing of a 12 IBC valve at Alden Research
More informationMeasurement of Total Losses in Small Induction Motors
Measurement of Total Losses in Small Induction Motors Azzeddine Ferrah 1 and Jehad M. Al-Khalaf Bani Younis 2 1 Faculty of Engineering, P.O. Box: 7947 Sharjah, United Arab Emirates 2 College of Applied
More informationMotors and Variable Speed Drives for Pumps and Fans. Reid Hart, PE
Motors and Variable Speed Drives for Pumps and Fans Reid Hart, PE APEM Summer Forum June 2016 Wilsonville, Oregon PNNL-SA-118188 Outline Energy Performance Code Packages Variable speed drives & motors
More informationExcessive Heat In Electric Motors: A Common Root Cause of Insulation Failure
Excessive Heat In Electric Motors: A Common Root Cause of Insulation Failure Introduction Maintenance professionals widely accept predictive maintenance (PdM) as a significant means of cost savings. However,
More informationThermal Considerations: Assuring Performance of Vicors Maxi, Mini, Micro Series High-Density DC-DC Converter Modules
APPLICATION NOTE AN:106 Thermal Considerations: Assuring Performance of Vicors Maxi, Mini, Micro Series High-Density DC-DC Converter Modules By Jeff Ham Sr. Application Engineer As the modular DC-DC converter
More informationFAN PERFORMANCE MODULATION
FAN PERFORMANCE MODULATION Some fan systems have changing air requirement during operation, such as variable air volume systems, while others have changing pressure requirements; both airflow and pressure
More informationPIPELINE REPAIR OF CORROSION AND DENTS: A COMPARISON OF COMPOSITE REPAIRS AND STEEL SLEEVES
Proceedings of the 2014 10th International Pipeline Conference IPC2014 September 29 - October 3, 2014, Calgary, Alberta, Canada IPC2014-33410 PIPELINE REPAIR OF CORROSION AND DENTS: A COMPARISON OF COMPOSITE
More informationTransmission Error in Screw Compressor Rotors
Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 2008 Transmission Error in Screw Compressor Rotors Jack Sauls Trane Follow this and additional
More informationApplication Notes. Calculating Mechanical Power Requirements. P rot = T x W
Application Notes Motor Calculations Calculating Mechanical Power Requirements Torque - Speed Curves Numerical Calculation Sample Calculation Thermal Calculations Motor Data Sheet Analysis Search Site
More informationTransient Modeling of Vapor Compression Refrigeration Systems Using Measured Compressor COP
Purdue University Purdue e-pubs International Refrigeration and Air Conditioning Conference School of Mechanical Engineering 2004 Transient Modeling of Vapor Compression Refrigeration Systems Using Measured
More informationEffect of Compressor Inlet Temperature on Cycle Performance for a Supercritical Carbon Dioxide Brayton Cycle
The 6th International Supercritical CO2 Power Cycles Symposium March 27-29, 2018, Pittsburgh, Pennsylvania Effect of Compressor Inlet Temperature on Cycle Performance for a Supercritical Carbon Dioxide
More informationPerformance Rating of Airto-Air Heat Exchangers for Energy Recovery Ventilation Equipment
AHRI Standard 1060 (I-P) 2011 Standard for Performance Rating of Airto-Air Heat Exchangers for Energy Recovery Ventilation Equipment IMPORTANT SAFETY DISCLAIMER AHRI does not set safety standards and does
More informationPredicted availability of safety features on registered vehicles a 2015 update
Highway Loss Data Institute Bulletin Vol. 32, No. 16 : September 2015 Predicted availability of safety features on registered vehicles a 2015 update Prior Highway Loss Data Institute (HLDI) studies have
More informationSound Application Guide: Description and Ratings
Sound Application Guide: Description and Ratings AHRI SOUND STANDARD: DESCRIPTION AND RATINGS Table of Contents Overview..........................................................................4 AHRI
More informationAerodynamically induced power loss in hard disk drives
Microsyst Technol (2005) 11: 741 746 DOI 10.1007/s00542-005-0575-8 TECHNICAL PAPER Sung-Oug Cho Æ Seung-Yop Lee Æ Yoon-Chul Rhim Aerodynamically induced power loss in hard disk drives Received: 30 June
More informationPump Control Ball Valve for Energy Savings
VM PCBVES/WP White Paper Pump Control Ball Valve for Energy Savings Table of Contents Introduction............................... Pump Control Valves........................ Headloss..................................
More informationCommon recommendations
Motor Overview Why are motors important? What is a motor? Optimizing the motor component power factor efficiency and losses motor/load relationships standards Common recommendations Review of CD-ROM Industrial
More informationMASTER \ C. Idaho National Engineering Laboratory. INEL 96J014t we.l~%/0o/60 PREPRINT. MOTOR-OPERATOR GEARBOX EFFICIENCY 5 i u.
INEL 96J014t we.l~%/0o/60 PREPRINT \ C Idaho National Engineering Laboratory MOTOR-OPERATOR GEARBOX EFFICIENCY 5 i u.^ 1 Q Kevin G. DeWall, John C. Watkins, Donovan Bramwell The Fourth NRC/ASME Symposium
More informationDevelopment and Validation of a Finite Element Model of an Energy-absorbing Guardrail End Terminal
Development and Validation of a Finite Element Model of an Energy-absorbing Guardrail End Terminal Yunzhu Meng 1, Costin Untaroiu 1 1 Department of Biomedical Engineering and Virginia Tech, Blacksburg,
More informationDesigning a Mechanically Adjustable Speed Drive for AC Motor Applications to Eliminate Vibrations Without Additional Harmonics
Designing a Mechanically Adjustable Speed Drive for AC Motor Applications to Eliminate Vibrations Without Additional Harmonics Philip Corbin III, Flux Drive Founder/CEO 1. INTRODUCTION: With the advent
More informationNational comparison on verification of fuel dispensers
16 th International Congress of Metrology, 06011 (2013) DOI: 10.1051/ metrology/201306011 C Owned by the authors, published by EDP Sciences, 2013 National comparison on verification of fuel dispensers
More informationPerformance Rating of Single Package Vertical Air-Conditioners And Heat Pumps
ANSI/AHRI Standard 390 2003 Standard for Performance Rating of Single Package Vertical Air-Conditioners And Heat Pumps IMPORTANT SAFETY DISCLAIMER AHRI does not set safety standards and does not certify
More informationCh. 169 DIESEL SMOKE MEASUREMENT CHAPTER 169. DIESEL SMOKE MEASUREMENT PROCEDURE
Ch. 169 DIESEL SMOKE MEASUREMENT 67 169.1 CHAPTER 169. DIESEL SMOKE MEASUREMENT PROCEDURE Sec. 169.1. Purpose. 169.2. Scope. 169.3. Definitions. 169.4. Smoke emission test. 169.5. Smoke test cycle. 169.6.
More informationOriginal. M. Pang-Ngam 1, N. Soponpongpipat 1. Keywords: Optimum pipe diameter, Total cost, Engineering economic
Original On the Optimum Pipe Diameter of Water Pumping System by Using Engineering Economic Approach in Case of Being the Installer for Consuming Water M. Pang-Ngam 1, N. Soponpongpipat 1 Abstract The
More informationChapter 10 Parametric Studies
Chapter 10 Parametric Studies 10.1. Introduction The emergence of the next-generation high-capacity commercial transports [51 and 52] provides an excellent opportunity to demonstrate the capability of
More informationOn Control Strategies for Wind Turbine Systems
On Control Strategies for Wind Turbine Systems Niall McMahon December 21, 2011 More notes to follow at: http://www.niallmcmahon.com/msc_res_notes.html 1 Calculations for Peak Tip Speed Ratio Assuming that
More informationWelded Steel Conveyor Pulleys
ANSI / CEMA B105.1-2009 A REVISION OF ANSI/CEMA B105.1-2003 (Approved May 19, 2009) CEMA Standard B105.1 Specifications for Welded Steel Conveyor Pulleys With Compression Type Hubs Conveyor Equipment Manufacturers
More informationRULES PUBLICATION NO. 98/P
RULES PUBLICATION NO. 98/P GUIDELINES REGARDING THE REQUIREMENTS FOR MARINE DIESEL ENGINES FITTED WITH NO X SELECTIVE CATALYTIC REDUCTION (SCR) SYSTEMS 2016 January Publications P (Additional Rule Requirements)
More informationInfluence of Parameter Variations on System Identification of Full Car Model
Influence of Parameter Variations on System Identification of Full Car Model Fengchun Sun, an Cui Abstract The car model is used extensively in the system identification of a vehicle suspension system
More informationTechnical Guide No. 7. Dimensioning of a Drive system
Technical Guide No. 7 Dimensioning of a Drive system 2 Technical Guide No.7 - Dimensioning of a Drive system Contents 1. Introduction... 5 2. Drive system... 6 3. General description of a dimensioning
More informationInvestigation in to the Application of PLS in MPC Schemes
Ian David Lockhart Bogle and Michael Fairweather (Editors), Proceedings of the 22nd European Symposium on Computer Aided Process Engineering, 17-20 June 2012, London. 2012 Elsevier B.V. All rights reserved
More informationI. INTRODUCTION. Sehsah, E.M. Associate Prof., Agric. Eng. Dept Fac, of Agriculture, Kafr El Sheikh Univ.33516, Egypt
Manuscript Processing Details (dd/mm/yyyy) : Received : 14/09/2013 Accepted on : 23/09/2013 Published : 13/10/2013 Study on the Nozzles Wear in Agricultural Hydraulic Sprayer Sehsah, E.M. Associate Prof.,
More informationWhite Paper. Improving Accuracy and Precision in Crude Oil Boiling Point Distribution Analysis. Introduction. Background Information
Improving Accuracy and Precision in Crude Oil Boiling Point Distribution Analysis. Abstract High Temperature Simulated Distillation (High Temp SIMDIS) is one of the most frequently used techniques to determine
More informationPerformance of DC Motor Supplied From Single Phase AC-DC Rectifier
Performance of DC Motor Supplied From Single Phase AC-DC Rectifier Dr Othman A. Alnatheer Energy Research Institute-ENRI King Abdulaziz City for Science and Technology- KACST P O Box 6086, Riyadh 11442,
More informationThe Mechanics of Tractor - Implement Performance
The Mechanics of Tractor - Implement Performance Theory and Worked Examples R.H. Macmillan CHAPTER 3 TRACTOR PERFORMANCE ON FIRM SURFACE Printed from: http://www.eprints.unimelb.edu.au CONTENTS 3.1 INTRODUCTION
More informationThe New EMC Requirements of Electric Cars
The New EMC Requirements of Electric Cars Author : Michael Koffink and Roland Gubisch 05/24/2009 Refinements are needed for better correlation between chip-level or module-level measurements and whole
More informationHigh-voltage Direct Inverter Applied to Induced Draft Fan Motor at Takehara Thermal Power Station No. 3 of Electric Power Development Co., Ltd.
Hitachi Review Vol. 53 (2004), No. 3 121 High-voltage Direct Inverter Applied to Induced Draft Fan Motor at Takehara Thermal Power Station No. 3 of Electric Power Development Co., Ltd. Hiroaki Yamada Kiyoshi
More informationDiesel-Driven Compressor Torque Pulse Measurement in a Transport Refrigeration Unit
Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 214 Diesel-Driven Compressor Torque Pulse Measurement in a Transport Refrigeration Unit
More informationEXPERIMENTAL STUDY OF DYNAMIC THERMAL BEHAVIOUR OF AN 11 KV DISTRIBUTION TRANSFORMER
Paper 110 EXPERIMENTAL STUDY OF DYNAMIC THERMAL BEHAVIOUR OF AN 11 KV DISTRIBUTION TRANSFORMER Rafael VILLARROEL Qiang LIU Zhongdong WANG The University of Manchester - UK The University of Manchester
More informationTitle: Optimal Design of a Thermoelectric Cooling/Heating for Car Seat Comfort Developed by Dr. HoSung Lee on 10/18/2014 Car seat comfort is becoming
Title: Optimal Design of a Thermoelectric Cooling/Heating for Car Seat Comfort Developed by Dr. HoSung Lee on 10/18/2014 Car seat comfort is becoming more and more a competitive issue, moving optional
More informationInvestigating the Concordance Relationship Between the HSA Cut Scores and the PARCC Cut Scores Using the 2016 PARCC Test Data
Investigating the Concordance Relationship Between the HSA Cut Scores and the PARCC Cut Scores Using the 2016 PARCC Test Data A Research Report Submitted to the Maryland State Department of Education (MSDE)
More informationEfficiency Increment on 0.35 mm and 0.50 mm Thicknesses of Non-oriented Steel Sheets for 0.5 Hp Induction Motor
International Journal of Materials Engineering 2012, 2(2): 1-5 DOI: 10.5923/j.ijme.20120202.01 Efficiency Increment on 0.35 mm and 0.50 mm Thicknesses of Non-oriented Steel Sheets for 0.5 Hp Induction
More informationModern Pump Selection for System Efficiency. By: Kyle DelPiano - Business Development Manager, Bell & Gossett
Modern Pump Selection for System Efficiency By: Kyle DelPiano - Business Development Manager, Bell & Gossett Our Seminar Goal!! Be REALISTIC and Honest regarding variable speed pumping. Actual efficiency
More informationPERFORMANCE CHARACTERIZATION OF NICD BATTERY BY ARBIN BT2000 ANALYZER IN BATAN
MATERIALS SCIENCE and TECHNOLOGY Edited by Evvy Kartini et.al. PERFORMANCE CHARACTERIZATION OF NICD BATTERY BY ARBIN BT2000 ANALYZER IN BATAN H. Jodi, E. Kartini, T. Nugraha Center for Technology of Nuclear
More informationExecutive Summary. Light-Duty Automotive Technology and Fuel Economy Trends: 1975 through EPA420-S and Air Quality July 2006
Office of Transportation EPA420-S-06-003 and Air Quality July 2006 Light-Duty Automotive Technology and Fuel Economy Trends: 1975 through 2006 Executive Summary EPA420-S-06-003 July 2006 Light-Duty Automotive
More information