Mathematical Reference

Total Page:16

File Type:pdf, Size:1020Kb

Mathematical Reference TRNSYS 16 a TRaNsient SYstem S imulation program Volume 5 Mathematical Reference Solar Energy Laboratory, Univ. of Wisconsin-Madison http://sel.me.wisc.edu/trnsys TRANSSOLAR Energietechnik GmbH http://www.transsolar.com CSTB – Centre Scientifique et Technique du Bâtiment http://software.cstb.fr TESS – Thermal Energy Systems Specialists http://www.tess-inc.com TRNSYS 16 – Mathematical Reference About This Manual The information presented in this manual is intended to provide a detailed mathematical reference for the Standard Component Library in TRNSYS 16. This manual is not intended to provide detailed reference information about the TRNSYS simulation software and its utility programs. More details can be found in other parts of the TRNSYS documentation set. The latest version of this manual is always available for registered users on the TRNSYS website (see here below). Revision history • 2004-09 For TRNSYS 16.00.0000 • 2005-02 For TRNSYS 16.00.0037 • 2006-03 For TRNSYS 16.01.0000 • 2007-03 For TRNSYS 16.01.0003 Where to find more information Further information about the program and its availability can be obtained from the TRNSYS website or from the TRNSYS coordinator at the Solar Energy Lab: TRNSYS Coordinator Email: [email protected] Solar Energy Laboratory, University of Wisconsin-Madison Phone: +1 (608) 263 1586 1500 Engineering Drive, 1303 Engineering Research Building Fax: +1 (608) 262 8464 Madison, WI 53706 – U.S.A. TRNSYS website: http://sel.me.wisc.edu/trnsys Notice This report was prepared as an account of work partially sponsored by the United States Government. Neither the United States or the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontractors, or employees, including but not limited to the University of Wisconsin Solar Energy Laboratory, makes any warranty, expressed or implied, or assumes any liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights. © 2006 by the Solar Energy Laboratory, University of Wisconsin-Madison The software described in this document is furnished under a license agreement. This manual and the software may be used or copied only under the terms of the license agreement. Except as permitted by any such license, no part of this manual may be copied or reproduced in any form or by any means without prior written consent from the Solar Energy Laboratory, University of Wisconsin-Madison. 5–2 TRNSYS 16 – Mathematical Reference TRNSYS Contributors S.A. Klein W.A. Beckman J.W. Mitchell J.A. Duffie N.A. Duffie T.L. Freeman J.C. Mitchell J.E. Braun B.L. Evans J.P. Kummer R.E. Urban A. Fiksel J.W. Thornton N.J. Blair P.M. Williams D.E. Bradley T.P. McDowell M. Kummert D.A. Arias Additional contributors who developed components that have been included in the Standard Library are listed in their respective section. Contributors to the building model (Type 56) and its interface (TRNBuild) are listed in Volume 6. Contributors to the TRNSYS Simulation Studio are listed in Volume 2. 5–3 TRNSYS 16 – Mathematical Reference 5–4 TRNSYS 16 – Mathematical Reference TABLE OF CONTENTS 5. MATHEMATICAL REFERENCE 5–9 5.1. Controllers 5–11 5.1.1. Type 2: Differential Controller 5–15 5.1.2. Type 8: Three Stage Room Thermostat 5–17 5.1.3. Type 22: Iterative Feedback Controller 5–19 5.1.4. Type 23: PID Controller 5–23 5.1.5. Type 40: Microprocessor Controller 5–28 5.1.6. Type 108: Five Stage Room Thermostat 5–34 5.2. Electrical 5–38 5.2.1. Type 47: Shepherd and Hyman Battery Models 5–39 5.2.2. Type 48: Regulator / Inverter 5–44 5.2.3. Type 50: PV-Thermal Collector 5–47 5.2.4. Type 90: Wind Energy Conversion System 5–49 5.2.5. Type 94: Photovoltaic array 5–67 5.2.6. Type 102: DEGS Dispatch controller 5–77 5.2.7. Type 120: Diesel Engine Generator Set 5–79 5.2.8. Type 175: Power conditioning unit 5–83 5.2.9. Type 180: Photovoltaic array (with data file) 5–85 5.2.10. Type 185: Lead-acid battery with gassing effects 5–91 5.2.11. Type 188: AC-busbar 5–97 5.2.12. Type 194: Photovoltaic array 5–99 5.3 Heat Exchangers 5–107 5.2.1 Type 5: Heat Exchanger 5–109 5.2.2 Type 17: Waste Heat Recovery 5–115 5.2.3 Type 91: Constant Effectiveness Heat Exchanger 5–117 5.3 HVAC 5–119 5.3.1 Type 6: Auxiliary heater 5–121 5.3.2 Type 20: Dual Source Heat Pump 5–123 5.3.3 Type 32: Simplified Cooling Coil 5–127 5.3.4 Type 42: Conditioning Equipment 5–131 5.3.5 Type 43: Part Load Performance 5–133 5.3.6 Type 51: Cooling Tower 5–135 5.3.7 Type 52: Detailed Cooling Coil 5–141 5.3.8 Type 53: Parallel Chillers 5–149 5.3.9 Type 92: ON/OFF Auxiliary Cooling Device 5–153 5.3.10 Type 107: Single Effect Hot Water Fired Absorption Chiller 5–155 5.3.11 Type 121: Simple Furnace / Air Heater 5–161 5–5 TRNSYS 16 – Mathematical Reference 5.4 Hydrogen Systems 5–163 5.4.1 Type 100: Electrolyzer controller 5–165 5.4.2 Type 105: Master level controller for SAPS 5–167 5.4.3 Type 160: Advanced Alkaline Electrolyzer 5–171 5.4.4 Type 164: Compressed gas storage 5–177 5.4.5 Type 167: Multistage compressor 5–179 5.4.6 Type 170: Proton-Exchange Membrane Fuel Cell 5–181 5.4.7 Type 173: Alkaline Fuel Cell 5–189 5.5 Hydronics 5–191 5.5.1 Type 3: Variable Speed Pump or Fan without Humidity Effects 5–193 5.5.2 Type 11: Tee Piece, Flow Diverter, Flow Mixer, Tempering Valve 5–195 5.5.3 Type 13: Pressure Relief Valve 5–199 5.5.4 Type 31: Pipe Or Duct 5–201 5.5.5 Type 110: Variable Speed Pump 5–204 5.5.6 Type 111: Variable Speed Fan/Blower with Humidity Effects 5–206 5.5.7 Type 112: Single Speed Fan/Blower with Humidity Effects 5–208 5.5.8 Type 114: Constant Speed Pump 5–210 5.6 Loads and Structures 5–212 5.6.1 Type 12: Energy/(Degree Day) Space Heating or Cooling Load 5–214 5.6.2 Type 18: Pitched Roof and Attic 5–220 5.6.3 Type 19: Detailed Zone (Transfer Function) 5–224 5.6.4 Type 34: Overhang and Wingwall Shading 5–237 5.6.5 Type 35: Window with Variable Insulation 5–241 5.6.6 Type 36: Thermal Storage Wall 5–243 5.6.7 Type 37: Attached Sunspace 5–249 5.6.8 Type 56: Multi-Zone Building and TRNBuild 5–253 5.6.9 Type 88: Lumped Capacitance BuildingType 5–255 5.7 Obsolete 5–257 5.8 Output 5–259 5.8.1 Type 25: Printer 5–261 5.8.2 Type 27: Histogram plotter 5–263 5.8.3 Type 28: Simulation Summary 5–265 5.8.4 Type 29: Economic analysis 5–272 5.8.5 Type 65: Online plotter 5–280 5.9 Physical Phenomena 5–284 5.9.1 Type 16: Solar Radiation Processor 5–286 5.9.2 Type 30: Collector Array Shading 5–296 5.9.3 Type 33: Psychrometrics 5–300 5.9.4 Type 54: Hourly Weather Data Generator 5–302 5.9.5 Type 58: Refrigerant Properties 5–306 5–6 TRNSYS 16 – Mathematical Reference 5.9.6 Type 59: Lumped capacitance model 5–308 5.9.7 Type63: Thermodynamic properties of substances with NASA CEA2 5–309 5.9.8 Type 64: Shading By External Object with Single Shading Mask 5–311 5.9.9 Type 67: Shading By External Object 5–313 5.9.10 Type 68: Shading By External Object 5–323 5.9.11 Type 69: Effective Sky Temperature 5–325 5.9.12 Type 77: Simple Ground Temperature Profile 5–327 5.9.13 Type 80: Calculation of Convective Heat Transfer Coefficients 5–329 5.10 Solar Thermal Collectors 5–331 5.10.1 Type 1: Flat-plate collector (Quadratic efficiency) 5–333 5.10.2 Type 45: Thermosyphon collector with integral collector storage 5–339 5.10.3 Type71: Evacuated tube solar collector 5–345 5.10.4 Type 72: Performance Map Solar Collector 5–351 5.10.5 Type 73: Theoretical flat-plate collector 5–357 5.10.6 Type 74: Compound Parabolic Concentrating Collector 5–361 5.11 Thermal Storage 5–367 5.11.1 Type 4: Stratified Fluid Storage Tank 5–369 5.11.2 Type 10: Rock bed storage 5–375 5.11.3 Type 38: Algebraic tank (Plug-flow) 5–379 5.11.4 Type 39: Variable volume tank 5–385 5.11.5 Type 60: Stratified fluid storage tank with internal heat exchangers 5–389 5.12 Utility 5–395 5.12.1 Type 9: Data reader (Generic data files) 5–397 5.12.2 Type14: Time dependent forcing function 5–408 5.12.3 Type 21: Time Values 5–410 5.12.4 Type 24: Quantity integrator 5–412 5.12.5 Type 41: Forcing function sequencer 5–414 5.12.6 Type 55: Periodic integrator 5–416 5.12.7 Type 57: Unit conversion routine 5–420 5.12.8 Type 62: Calling Excel 5–426 5.12.9 Type 66: Calling Engineering Equation Solver (EES) Routines 5–428 5.12.10 Type 70: Parameter replacement 5–432 5.12.11 Type 81: 1D interpolation from file 5–435 5.12.12 Type 83: Differentiation of a signal 5–436 5.12.13 Type 84: Moving Average 5–438 5.12.14 Type 89: Weather data reader (standard format) 5–440 5.12.15 Type 93: Input value recall 5–442 5.12.16 Type 95: Holiday calculator 5–444 5.12.17 Type 96: Utility rate schedule processor 5–448 5.12.18 Type 97: Calling CONTAM 5–456 5.12.19 Type 101: Calling FLUENT 5–459 5–7 TRNSYS 16 – Mathematical Reference 5.12.20 Type 155: Calling Matlab 5–461 5.12.21 Type157: Calling COMIS 5–466 5.13 Weather Data Reading and Processing 5–468 5.14.1 Type 15: Weather Data Processor 5–470 5.14.2 Type 109: Combined data reader and solar radiation processor 5–474 5.15.
Recommended publications
  • Psychrometrics Outline
    Psychrometrics Outline • What is psychrometrics? • Psychrometrics in daily life and food industry • Psychrometric chart – Dry bulb temperature, wet bulb temperature, absolute humidity, relative humidity, specific volume, enthalpy – Dew point temperature • Mixing two streams of air • Heating of air and using it to dry a product 2 Psychrometrics • Psychrometrics is the study of properties of mixtures of air and water vapor • Water vapor – Superheated steam (unsaturated steam) at low pressure – Superheated steam tables are on page 817 of textbook – Properties of dry air are on page 818 of textbook – Psychrometric charts are on page 819 & 820 of textbook • What are these properties of interest and why do we need to know these properties? 3 Psychrometrics in Daily Life • Sea breeze and land breeze – When and why do we get them? • How do thunderstorms, hurricanes, and tornadoes form? • What are dew, fog, mist, and frost and when do they form? • When and why does the windshield of a car fog up? – How do you de-fog it? Is it better to blow hot air or cold air? Why? • Why do you feel dry in a heated room? – Is the moisture content of hot air lower than that of cold air? • How does a fan provide relief from sweating? • How does an air conditioner provide relief from sweating? • When does a soda can “sweat”? • When and why do we “see” our breath? • Do sailboats perform better at high or low relative humidity? Key factors: Temperature, Pressure, and Moisture Content of Air 4 Do Sailboats Perform Better at low or High RH? • Does dry air or moist air provide more thrust against the sail? • Which is denser – humid air or dry air? – Avogadro’s law: At the same temperature and pressure, the no.
    [Show full text]
  • Performance of Rotary Enthalpy Exchangers
    PERFORMANCE OF ROTARY ENTHALPY EXCHANGERS by GUNNAR STIESCH A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE (Mechanical Engineering) at the UNIVERSITY OF WISCONSIN-MADISON 1994 ABSTRACT Rotary regenerative heat and mass exchangers allow energy savings in the heating and cooling of ventilated buildings by recovering energy from the exhaust air and transferring it to the supply air stream. In this study the adsorption isotherms and the specific heat capacity of a desiccant used in a commercially available enthalpy exchanger are investigated experimentally, and the measured property data are used to simulate the regenerator performance and to analyze the device in terms of both energy recovery and economic profitability. Based on numerical solutions for the mechanism of combined heat and mass transfer obtained with the computer program MOSHMX for various operating conditions, a computationally simple model is developed that estimates the performance of the particular enthalpy exchanger and also of a comparable sensible heat exchanger as a function of the air inlet conditions and the matrix rotation speed. The model is built into the transient simulation program TRNSYS, and annual regenerator performance simulations are executed. The integrated energy savings over this period are determined for the case of a ventilation system for a 200 people office building (approx. 2 m3/s) for three different locations in the United States, each representing a different climate. Life cycle savings that take into account the initial cost of the space-conditioning system as well as the operating savings achieved by the regenerator are evaluated for both the enthalpy exchanger and the sensible heat exchanger over a system life time of 15 years.
    [Show full text]
  • Teaching Psychrometry to Undergraduates
    AC 2007-195: TEACHING PSYCHROMETRY TO UNDERGRADUATES Michael Maixner, U.S. Air Force Academy James Baughn, University of California-Davis Michael Rex Maixner graduated with distinction from the U. S. Naval Academy, and served as a commissioned officer in the USN for 25 years; his first 12 years were spent as a shipboard officer, while his remaining service was spent strictly in engineering assignments. He received his Ocean Engineer and SMME degrees from MIT, and his Ph.D. in mechanical engineering from the Naval Postgraduate School. He served as an Instructor at the Naval Postgraduate School and as a Professor of Engineering at Maine Maritime Academy; he is currently a member of the Department of Engineering Mechanics at the U.S. Air Force Academy. James W. Baughn is a graduate of the University of California, Berkeley (B.S.) and of Stanford University (M.S. and PhD) in Mechanical Engineering. He spent eight years in the Aerospace Industry and served as a faculty member at the University of California, Davis from 1973 until his retirement in 2006. He is a Fellow of the American Society of Mechanical Engineering, a recipient of the UCDavis Academic Senate Distinguished Teaching Award and the author of numerous publications. He recently completed an assignment to the USAF Academy in Colorado Springs as the Distinguished Visiting Professor of Aeronautics for the 2004-2005 and 2005-2006 academic years. Page 12.1369.1 Page © American Society for Engineering Education, 2007 Teaching Psychrometry to Undergraduates by Michael R. Maixner United States Air Force Academy and James W. Baughn University of California at Davis Abstract A mutli-faceted approach (lecture, spreadsheet and laboratory) used to teach introductory psychrometric concepts and processes is reviewed.
    [Show full text]
  • Understanding Psychrometrics, Third Edition It’S Really a Mine of Information
    Gatley The Comprehensive Guide to Psychrometrics Understanding Psychrometrics serves as a lifetime reference manual and basic refresher course for those who use psychrometrics on a recurring basis and provides a four- to six-hour psychrometrics learning module to students; air- conditioning designers; agricultural, food process, and industrial process engineers; Understanding Psychrometrics meteorologists and others. Understanding Psychrometrics Third Edition New in the Third Edition • Revised chapters for wet-bulb temperature and relative humidity and a revised Appendix V that includes a summary of ASHRAE Research Project RP-1485. • New constants for the universal gas constant based on CODATA and a revised molar mass of dry air to account for the increase of CO2 in Earth’s atmosphere. • New IAPWS models for the calculation of water properties above and below freezing. • New tables based on the ASHRAE RP-1485 real moist-air numerical model using the ASHRAE LibHuAirProp add-ins for Excel®, MATLAB®, Mathcad®, and EES®. Includes Access to Bonus Materials and Sample Software • PDF files of 13 ultra-high-pressure and 12 existing ASHRAE psychrometric charts plus three new 0ºC to 400ºC charts. • A limited demonstration version of the ASHRAE LibHuAirProp add-in that allows users to duplicate portions of the real moist-air psychrometric tables in the ASHRAE Handbook—Fundamentals for both standard sea level atmospheric pressure and pressures from 5 to 10,000 kPa. • The hw.exe program from the second edition, included to enable users to compare the 2009 ASHRAE numerical model real moist-air psychrometric properties with the 1983 ASHRAE-Hyland-Wexler properties. Praise for Understanding Psychrometrics, Third Edition It’s really a mine of information.
    [Show full text]
  • Basics of Psychrometrics Practical Heat Load Calculation
    Basics of Psychrometrics Practical Heat Load Calculation Webinar 30 April 2020 Vikram Murthy ASHRAE Mumbai Chapter Sessions ►Basics of Psychrometrics ►All about Heat ►Practical Heat Load (Cooling Load) Calculation ( Using the E 20 , CLTD - Cooling Load Temperature Difference Method ) Psychrometric basics Psychrometrics ► A hundred and eighteen years ago, Willis Carrier, developed a method that allows us to visualize two of the variables -- the combination of air temperature and humidity that exist in a space. The tool he developed is called the Psychrometric Chart. ► Psychrometrics, which Willis Carrier developed, is the study of the mixture of dry air and water , and is the scientific basis of Air conditioning . Willis Carrier Willis began his first job at the Buffalo Forge Company . Solving a Problem at the Sackett Wilhelm Lithographing Company in Brooklyn, he formulated the Laws of Psychrometrics . Willis Carrier laid down the Equations of Psychrometrics in 1902 . The Carrier Company he founded developed the Centrifugal Chiller and the Weathermaker, that we call an Air Handling Unit or AHU . Purpose Of Comfort Airconditioning ►To Cool or Heat ►To Dehumidify or Humidify (remove or add moisture) ►To remove odours ►To remove particulate & microbial pollutants Definitions Of Air ► Air is a vital component of our everyday lives. ► Psychrometrics refers to the properties of moist air. ► Dry air ► Moist air ► Moist air and atmospheric air can be considered to mean the same Units ► We work in INCH POUND system of units, IP units. (The other unit system in use is SI units) Units of length: ft, inches. Units of area: sq.ft Units of volume: cu.ft.
    [Show full text]
  • Psychrometrics and Postharvest Operations 1
    Archival copy: for current recommendations see http://edis.ifas.ufl.edu or your local extension office. CIR1097 Psychrometrics and Postharvest Operations 1 Michael T. Talbot and Direlle Baird2 The Florida commercial vegetable industry is reviews how they can be measured. This publication large and diverse and the value of vegetable further suggests how the psychrometric variables can production in the state of Florida is over 1.5 billion be used and more importantly how they should be dollars annually. Most of these vegetable crops are used by managers. produced for the fresh market and require proper postharvest control to maintain quality and reduce Psychrometric Variables spoilage. The ambient environment to which the Atmospheric air contains many gaseous freshly harvested vegetables are exposed has a very components as well as water vapor. Dry air is a significant effect on the postharvest life of these mixture of nitrogen (78%), oxygen (21%), and perishable commodities. argon, carbon dioxide, and other minor constituents Psychrometrics deals with thermodynamic (1%). Moist air is a two-component mixture of dry properties of moist air and the use of these properties air and water vapor. The amount of water vapor in to analyze conditions and processes involving moist moist air varies from zero (dry air) to a maximum air [1, 7] (numbers in brackets refer to cited (saturation) which depends on temperature and references). Commonly used psychrometric variables pressure. Even though water vapor represents only are temperature, relative humidity, dew point 0.4 to 1.5% of the weight of the air, water vapor plays temperature, and wet bulb temperature.
    [Show full text]
  • Introduction to HVAC Systems, Thermal Comfort and Indoor Air Quality 1
    (All new additions since the 2017 Learning Objectives have been Italicized) Introduction to HVAC Systems, Thermal Comfort and Indoor Air Quality 1. Describe the typical functions of an HVAC system 2. Describe the difference between “all air systems”, “air/water systems” and “all water systems” 3. Describe how commercial HVAC design differs from residential design 4. Discuss the different terms used for heating and cooling equipment efficiency and capacity 5. Recognize the advantages and disadvantages of the various conditioning systems 6. Describe the importance of establishing zones for the purposes of space conditioning 7. Describe the importance of the ASHRAE comfort zone and explain the difference between Predicted Mean Vote and Predicted Percent Dissatisfied 8. Define “operative temperature” and demonstrate how it is calculated 9. List common indoor air contaminants and their sources including PM2.5, Second Hand Smoke, CO, Radon, Ozone, Formaldehyde, Acrolein, Mould, CO2 10. Calculate the concentration of various contaminants given rates of contaminant generation 11. Describe how indoor contaminants can be controlled through source control, air exchange, air filtration 12. Calculate the outdoor air requirement for a zone according to ASHRAE Standard 62 13. Define ventilation effectiveness and be able to calculate it Thermodynamics 14. Calculate state properties of moist air, refrigerant, and steam 15. Explain the thermodynamic cycles that are relevant to HVAC (Carnot, Reverse Carnot, Rankine Power, Rankine Refrigeration) Psychrometrics 16. Describe the difference between sensible and latent heat energy in moist air 17. Demonstrate how the psychrometric chart can be used to illustrate common HVAC processes (e.g. air mixing, heating and humidification, typical air conditioning) and the impact of these processes on dry and wet bulb temperature, relative humidity, enthalpy and moisture content 18.
    [Show full text]
  • Mold, Moisture, and Houses – Ventilation Is an Effective Weapon 1 June 2009
    Mold, Moisture, and Houses – Ventilation is an Effective Weapon 1 June 2009 MOLD, MOISTURE, AND HOUSES – VENTILATION IS AN EFFECTIVE WEAPON This guideline document provides an overview of residential mold prevention in plain language that may be understood by the average consumer – the resident of today’s North American housing. It provides a basic scientific explanation of mold fundamentals, findings related to problems blamed on mold, and an introduction to psychrometrics - the science of air containing moisture. That scientific base is then applied as a general guideline for making the practical decisions associated with residential design, construction, ventilation and operation for effective mold control. Written by: David W. Wolbrink With inputs from: Rick Olmstead, Paul H. Raymer, Donald T. Stevens, John Ehlen, James D. Boldt, Daniel T. Forest, Gord Arnott, Joel Borque Home Ventilating Institute 1000 North Rand Road, Suite 214 Wauconda, IL 60084 USA Phone: 847.526.2010 Fax: 847.526.2993 e-mail: [email protected] Website: www.hvi.org Copyright © 2009 Home Ventilating Institute TABLE OF CONTENTS 1. Executive Summary........................................................................................ 2 2. Introduction to This Guideline......................................................................... 3 3. Mold: Friend and Enemy................................................................................. 4 4. Moisture and Air Around Us............................................................................ 7 5. The House:
    [Show full text]
  • Simulation and Comparative Study of a Hybrid Cooling Solar – Gas with Heat Storage
    Available online at www.sciencedirect.com ScienceDirect Energy Procedia 57 ( 2014 ) 2646 – 2655 2013 ISES Solar World Congress Simulation and Comparative Study of a Hybrid Cooling Solar – Gas with Heat Storage Pando Martínez GEa,b*,Sauceda Carvajal Dc,Velázquez Limón Na,Luna León Ad, b Moreno Hernandez C aCentro de Estudios de las Energías Renovables, Instituto de Ingeniería, Universidad Autonóma de Baja California, Calle de la normal s/n col. Insurgentes, Mexicali, B.C. 21280, México. bInstituto Tecnológico de Hermosillo,Av. Tecnológico s/n col. El Sahuaro, Hermosillo, Son., 83170, México . c Facultad de Ingeniería, Universidad Autonóma de Baja California, Calle de la normal s/n col. Insurgentes, Mexicali, B.C. 21280, México. d Facultad de Arquitectura, Universidad Autonóma de Baja California, Calle de la normal s/n col. Insurgentes, Mexicali, B.C. 21280, México. Abstract In this paper, we show a comparison between an absorption chiller with direct fire activated and a hybrid solar-gas absorption chiller, with a cooling capacity of 17.6 kW each (5 TR) installed in a residence located in Mexicali, BC Mexico, to do simulations were performed during the summer of the town using dynamic simulation through the environment TRNSYS 16 mainly obtained LP gas consumption and the reduction in the consumption of it to use solar energy as a heat source in the generator. To produce the required heat used eight parabolic trough collectors configuring them as follows: 4 collectors in parallel and in series 2 collectors results show a reduction in LP gas consumption of approximately 24% during the period evaluated. © 2014 The Authors.
    [Show full text]
  • 0718 Psychrometrics 022 025.Pdf
    A look at the science of psychrometrics, and a real life example of how it can be used in the field to deliver lasting comfort to customers. BY CAMERON TAYLOR, CM Images courtesy of Fieldpiece Instruments Inc, unless otherwise noted. sychrometrics is simply defined as the measurement of temperature and water vapor mixtures in a given sample Pof air. It is a subject that nearly all HVAC students are taught, and many often struggle to master. It is also almost always taught in an HVAC design con- text; less so from a perspective of field analysis and trouble- shooting. Students who go on to become service technicians often wonder why they were taught psychrometrics when they perceive how seldom they use it in the field. This should not Sensible heat transfer methods (conduction, convection be so, as psychrometrics is the very foundation of HVAC, and radiation) explained visually. Image credit: Nate Adams, both in terms of design/engineering, and in field analysis. “The Home Comfort Book”. The reason we have HVAC in buildings is for human comfort, and the basis for proper HVAC design and function is psychrometrics. Understanding what is required to make Four forms of heat transfer humans comfortable indoors is also foundational for effectively The human body relies on two basic forms of heat transfer designing, installing and servicing HVAC systems. for comfort: sensible and latent heat. Within the sensible transfer form are three methods: convection, which is the Basis for human comfort transfer of heat by a fluid (such as air); conduction, which is The human body creates more heat than it needs, therefore the transfer of heat via solid objects; and radiation, which is the body will always reject this excess heat, regardless of the a transfer of heat via electromagnetic waves, such as the sun environment that surrounds it.
    [Show full text]
  • Table of Contents
    Table of Contents 1.0 Introduction ........................................................................................................................ 3 2.0 Key Terms .......................................................................................................................... 4 3.0 Key Equations .................................................................................................................... 6 4.0 Psychrometric Chart ........................................................................................................... 8 4.1 Properties of Moist Air .................................................................................................... 9 4.1.1 Dry Bulb Temperature ........................................................................................... 10 4.1.2 Wet Bulb Temperature .......................................................................................... 11 4.1.3 Relative Humidity .................................................................................................. 12 4.1.4 Humidity Ratio ....................................................................................................... 13 4.1.5 Enthalpy ................................................................................................................ 14 4.1.6 Specific Volume ..................................................................................................... 15 4.1.7 Dew Point .............................................................................................................
    [Show full text]
  • EFFICIENT COLLECTION and STORAGE of SOLAR ENERGY By
    EFFICIENT COLLECTION AND STORAGE OF SOLAR ENERGY By Eng. ADEL ALY AHMED GHONEIM A thesis Submitted for the degree of Doctor Of Philosophy In Engineering Physics at the FACULTY OF ENGINEERING UNIVERSITY OF ALEXANDRIA 1989 ABSTRACT Since solar energy is available only during daylight hours of a certain periods of the year, a means of providing heat on a continuous bases from this intermittent source is required. This can be done by storing energy during daylight hours for later use. Energy storage provides a useful means of improving solar system performance. In this thesis, detailed theoretical models have been developed for both sensible and phase-change energy storage units. The present detailed models took all the assumptions made in earlier studies into account. The transient simulation program (TRNSYS) developed at Solar Energy Laboratory, University of Wisconsin-Madison was used to determine the performance of the solar heating systems. A comparison was made between the solar system performance obtained using the present detailed models and the corresponding performance obtained using the assumptions made in earlier studies for both air and water-based active solar heating systems. The effects of varying the melting temperature and latent heat of the phase-change materials on the performance of air-based solar active heating systems were also examined. These effects were studied for different locations and different heating season months. A sensible energy storage material called 'Abu-Siebera clay', which is found in Abu-Siebera, Egypt was investigated to test its performance as a sensible store medium. The thermal properties of this material were measured experimentally in the Faculty of Engineering, University of Alexandria.
    [Show full text]