Psychrometrics Outline
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Energy Analysis and Carbon Saving Potential of a Complex Heating
European Journal of Sustainable Development Research 2019, 3(1), em0067 ISSN: 2542-4742 Energy Analysis and Carbon Saving Potential of a Complex Heating System with Solar Assisted Heat Pump and Phase Change Material (PCM) Thermal Storage in Different Climatic Conditions Uroš Stritih 1*, Eva Zavrl 1, Halime Omur Paksoy 2 1 University of Ljubljana, SLOVENIA 2 Çukurova Üniversitesi, TURKEY *Corresponding Author: [email protected] Citation: Stritih, U., Zavrl, E. and Paksoy, H. O. (2019). Energy Analysis and Carbon Saving Potential of a Complex Heating System with Solar Assisted Heat Pump and Phase Change Material (PCM) Thermal Storage in Different Climatic Conditions. European Journal of Sustainable Development Research, 3(1), em0067. https://doi.org/10.20897/ejosdr/3930 Published: February 6, 2019 ABSTRACT Building sector still consumes 40% of total energy consumption. Therefore, an improved heating system with Solar Assisted Heat Pump (SAHP) was introduced in order to minimse the energy consumption of the fossil fuels and to lower the carbon dioxide emissions occurring from combustion. An energy analysis of the complex heating system for heating of buildings, consisting of solar collectors (SC), latent heat storage tank (LHS) and heat pump (HP) was performed. The analysis was made for the heating season within the time from October to March for different climatic conditions. These climatic conditions were defined using test reference years (TRY) for cities: Adana, Ljubljana, Rome and Stockholm. The energy analysis was performed using a mathematical model which allowed hourly dynamics calculation of losses and gains for a given system. In Adana, Rome and Ljubljana, it was found that the system could cover 80% of energy from the sun and the heat pump coefficient of performance (COP) reached 5.7. -
Chapter 8 and 9 – Energy Balances
CBE2124, Levicky Chapter 8 and 9 – Energy Balances Reference States . Recall that enthalpy and internal energy are always defined relative to a reference state (Chapter 7). When solving energy balance problems, it is therefore necessary to define a reference state for each chemical species in the energy balance (the reference state may be predefined if a tabulated set of data is used such as the steam tables). Example . Suppose water vapor at 300 oC and 5 bar is chosen as a reference state at which Hˆ is defined to be zero. Relative to this state, what is the specific enthalpy of liquid water at 75 oC and 1 bar? What is the specific internal energy of liquid water at 75 oC and 1 bar? (Use Table B. 7). Calculating changes in enthalpy and internal energy. Hˆ and Uˆ are state functions , meaning that their values only depend on the state of the system, and not on the path taken to arrive at that state. IMPORTANT : Given a state A (as characterized by a set of variables such as pressure, temperature, composition) and a state B, the change in enthalpy of the system as it passes from A to B can be calculated along any path that leads from A to B, whether or not the path is the one actually followed. Example . 18 g of liquid water freezes to 18 g of ice while the temperature is held constant at 0 oC and the pressure is held constant at 1 atm. The enthalpy change for the process is measured to be ∆ Hˆ = - 6.01 kJ. -
Investigating Applicability of Evaporative Cooling Systems for Thermal Comfort of Poultry Birds in Pakistan
applied sciences Article Investigating Applicability of Evaporative Cooling Systems for Thermal Comfort of Poultry Birds in Pakistan Hafiz M. U. Raza 1, Hadeed Ashraf 1, Khawar Shahzad 1, Muhammad Sultan 1,* , Takahiko Miyazaki 2,3, Muhammad Usman 4,* , Redmond R. Shamshiri 5 , Yuguang Zhou 6 and Riaz Ahmad 6 1 Department of Agricultural Engineering, Bahauddin Zakariya University, Bosan Road, Multan 60800, Pakistan; [email protected] (H.M.U.R.); [email protected] (H.A.); [email protected] (K.S.) 2 Faculty of Engineering Sciences, Kyushu University, Kasuga-koen 6-1, Kasuga-shi, Fukuoka 816-8580, Japan; [email protected] 3 International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan 4 Institute for Water Resources and Water Supply, Hamburg University of Technology, Am Schwarzenberg-Campus 3, 20173 Hamburg, Germany 5 Leibniz Institute for Agricultural Engineering and Bioeconomy, Max-Eyth-Allee 100, 14469 Potsdam-Bornim, Germany; [email protected] 6 Bioenergy and Environment Science & Technology Laboratory, College of Engineering, China Agricultural University, Beijing 100083, China; [email protected] (Y.Z.); [email protected] (R.A.) * Correspondence: [email protected] (M.S.); [email protected] (M.U.); Tel.: +92-333-610-8888 (M.S.); Fax: +92-61-9210298 (M.S.) Received: 4 June 2020; Accepted: 24 June 2020; Published: 28 June 2020 Abstract: In the 21st century, the poultry sector is a vital concern for the developing economies including Pakistan. The summer conditions of the city of Multan (Pakistan) are not comfortable for poultry birds. -
Thermal Science Cooling Tower Performance Vs. Relative Humidity
thermal science Cooling Tower Performance vs. Relative Humidity BASIC THEORY AND PRACTICE Total Heat Exchange A mechanical draft cooling tower is a specialized heat exchanger G = mass rate of dry air [lb/min] in which two fluids (air and water) are in direct contact with each L = mass rate of circulating water [lb/min] other to induce the transfer of heat. Le = mass rate of evaporated water [lb/min] THW = temperature of hot water entering tower [°F] Ignoring any negligible amount of sensible heat exchange that TCW = temperature of cold water leaving tower [°F] hin = enthalpy of air entering [Btu/lb/dry air] may occur through the walls (casing) of the cooling tower, the heat hout = enthalpy of air leaving [Btu/lb/dry air] gained by the air must equal the heat lost by the water. This is Cp = specific heat of water = 4.18 [Btu/lb-°F] an enthalpy driven process. Enthalpy is the internal energy plus Win = humidity ratio of air entering [lb water/lb dry air] the product of pressure and volume. When a process occurs at Wout = humidity ratio of air leaving [lb water/lb dry air] constant pressure (atmospheric for cooling towers), the heat In order to know how much heat the air flowing through a cooling absorbed in the air is directly correlated to the change in enthalpy. tower can absorb, the enthalpy of the air entering the tower must This is shown in Equation 1. be known. This is shown on the psychrometric chart Figure 1. G (hout - hin) = L x Cp (THW - 32°) - Cp (L - Le)(TCW - 32°) (1) The lines of constant enthalpy are close to parallel to the lines of constant wet bulb. -
Recommended Qualification Test Procedure for Solar Absorber.Pdf
Date: 2004-09-10 Editor Bo Carlsson1 IEA Solar Heating and Cooling Program Task 27 Performance of Solar Façade Components Project: Service life prediction tools for Solar Collectors Recommended qualification test procedure for solar absorber surface durability 1 Address: SP Swedish National Testing and Research Institute, P.O.Box 857, SE-50115 Borås, e-mail: [email protected] Contents Page Foreword.............................................................................................................................................................iv Introduktion .........................................................................................................................................................v 1 Scope ......................................................................................................................................................1 2 Normative references ............................................................................................................................1 3 Terms and definitions ...........................................................................................................................2 4 Requirements and classification..........................................................................................................3 5 Test methods for assessing material properties as measure of absorber performance...............4 5.1 Sampling and preparation of test specimens.....................................................................................4 -
A Comprehensive Review of Thermal Energy Storage
sustainability Review A Comprehensive Review of Thermal Energy Storage Ioan Sarbu * ID and Calin Sebarchievici Department of Building Services Engineering, Polytechnic University of Timisoara, Piata Victoriei, No. 2A, 300006 Timisoara, Romania; [email protected] * Correspondence: [email protected]; Tel.: +40-256-403-991; Fax: +40-256-403-987 Received: 7 December 2017; Accepted: 10 January 2018; Published: 14 January 2018 Abstract: Thermal energy storage (TES) is a technology that stocks thermal energy by heating or cooling a storage medium so that the stored energy can be used at a later time for heating and cooling applications and power generation. TES systems are used particularly in buildings and in industrial processes. This paper is focused on TES technologies that provide a way of valorizing solar heat and reducing the energy demand of buildings. The principles of several energy storage methods and calculation of storage capacities are described. Sensible heat storage technologies, including water tank, underground, and packed-bed storage methods, are briefly reviewed. Additionally, latent-heat storage systems associated with phase-change materials for use in solar heating/cooling of buildings, solar water heating, heat-pump systems, and concentrating solar power plants as well as thermo-chemical storage are discussed. Finally, cool thermal energy storage is also briefly reviewed and outstanding information on the performance and costs of TES systems are included. Keywords: storage system; phase-change materials; chemical storage; cold storage; performance 1. Introduction Recent projections predict that the primary energy consumption will rise by 48% in 2040 [1]. On the other hand, the depletion of fossil resources in addition to their negative impact on the environment has accelerated the shift toward sustainable energy sources. -
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 -
Evaluation of the Effect of Relative Humidity of Air on the Coefficients of Critical Flow Venturi Nozzles
Evaluation of the Effect of Relative Humidity of Air on the Coefficients of Critical Flow Venturi Nozzles K. Chahine and M. Ballico National Measurement Institute, Australia P O Box 264, Lindfield, NSW 2070, Australia [email protected] Abstract atmospheric pressures. To establish stable sonic conditions in the nozzle, the down-stream end of the nozzle is usually connected to a high-capacity vacuum At NMIA, volumetric standards such as Brooks pump, with the up-stream end connected to the meter- or bell provers are used to calibrate critical flow Venturi under-test. During calibration the test-flowmeter draws nozzles or “sonic nozzles”. These nozzles, which are air from the laboratory at or near atmospheric pressures extremely stable, are used by both NMIA and Australian and temperature, and with relative humidity varying accredited laboratories to establish continuous flows for between 40% and 60%. The mass flowrate produced by the calibration of gas flow meters. For operational the nozzles is calculated based on the calibrated values of reasons, sonic nozzles are generally calibrated using dry the nozzle coefficient, the measured up-stream pressure air but later used with standard atmospheric air at various and the density calculated from the air temperature, humidity levels either drawn or blown through the meter- pressure and humidity [2]. under-test. Although the accepted theoretical calculations for determining the mass flow through a sonic nozzle At present, any effect of the relative humidity on the incorporate corrections for the resulting change in air nozzle coefficients is considered as negligible, as various density, as laboratories seek to reduce uncertainties the authors have estimated the systematic error at 0.02% for validity of this assumption warrants further examination. -
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. -
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. -
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. -
Model 1830, 1850 & 1850W Dehumidifier Owner's Manual
Model 1830, 1850 & 1850W Dehumidifier Owner’s Manual PLEASE LEAVE THIS MANUAL WITH THE HOMEOWNER Installed by: _________________________________ Installer Phone: _______________________ Date Installed: _______________ ON/OFF button Up/Down Dehumidifer Control Outlet used to turn buttons used to dehumidifier on change humidity and off setting MODE button used for optional ventilation feature Inlet Filter Access Drain Power Door Switch 90-1874 WHOLE HOME Dehumidification The Aprilaire® Dehumidifier controls the humidity level in your entire home. A powerful blower inside the dehumidifier draws air into the cabinet, filters the air and removes moisture, then discharges the dry air into the HVAC system or dedicated area of the home. Inside the cabinet, a sealed refrigeration system removes moisture by moving the air through a series of tubes and fins that are kept colder than the dew point of the incoming air. The dew point is the temperature at which moisture in the air will condense, much like what occurs on the outside of a cold glass on a hot summer day. The condensed moisture drips into the dehumidifier drain pan to a drain tube routed to the nearest floor drain or condensate pump. After the moisture is removed, the air moves through a second coil where it is reheated before being sent back into the home. The air leaving the dehumidifier will be warmer and drier than the air entering the dehumidifier. SETTING THE DESIRED HUMIDITY LEVEL The dehumidifier on-board control will display the humidity setting when not running, and ENERGY SavinGS TIPS displays the measured humidity when running. Energy Savings Tip #1: Adjust the humidity setting to be as high as is comfortable to reduce dehumidifier run time.