Engineering Fundamentals：part I Related to moist air and water

Slides:

Advertisements

Similar presentations

Tutorial for Psyc0226 Wei Fang, Ph.D., Professor

Advertisements

WCB/McGraw-Hill © The McGraw-Hill Companies, Inc.,1998 Thermodynamics Çengel Boles Third Edition 13 CHAPTER Gas-Vapor Mixtures and Air-Conditioning.

Heating and Air Conditioning I

Psychrometric Properties of Moist Air

Ta-Te Lin, Yi-Chung Chang

MOLLIER DIAGRAM.

Atmospheric Moisture. How does the moisture get in the atmosphere?? EVAPORATION TRANSPIRATION – water evaporated from trees.

10/28/97A F Emery1 PSYCHROMETRICS and ELEMENTARY PROCESSES (SI Units) Ashley F. Emery University of Washington.

Examples on using Psychart -- The digital psychrometric software

ARCH-432 Dew Point Saturation and Psychometrics. Attendance Who is typically referred to as the “Father of Cool”? (hint: generally credited with developing.

Psychrometrics.

Gas – Vapor Mixtures & Air – Conditioning

PSYCHROMETRIC CHART © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence.

Building Energy Efficiency

Bernoulli’s Theorem for Fans PE Review Session VIB – section 1.

PSYCHOMETRICS INTRODUCTION INDEXES PSYCHOMETRIC CHART INTRODUCTION:

Lecture 34 The Psychrometric Chart Psychrometric Properties in EES

Pump Affinity Laws. P. 100 of text – section 4: vary only speed of pump P. 100 of text – section 5: vary only diameter P. 106 of text – vary BOTH speed.

Core Principles Bernoulli’s theorem for Fans

Psychrometry HVAC CNST 305 Environmental Systems 1 Dr. Berryman 5cIndoor Air Quality, Psychometrics; Dry and Wet Bulb; Enthalpy; Condensation; Dew Point.

APPLIED THERMODYNAMICS, PSYCHROMETRY

Objectives Learn more about Psychrometrics

Objectives Learn about Psychometrics Psychometric chart Equations.

Department of Mechanical Engineering ME 322 – Mechanical Engineering Thermodynamics Lecture 35 Analysis of Air Conditioning Processes.

Asian Institute of Technology

Lab 5: Atmospheric Moisture.

10/28/97A F Emery1 PSYCHROMETRICS and ELEMENTARY PROCESSES (English Units) Ashley F. Emery University of Washington.

Saturation = filled to capacity

What is Fog? Fog is essentially a dense cloud of water droplets, or cloud, that is close to the ground. Fog forms when warm, moist air travels over a cold.

A Trane Air Conditioning Clinic Psychrometry Air Conditioning Clinic TRG-TRC001-EN © American Standard Inc

Objectives Finish with Heat transfer Learn about Psychometrics Psychometric chart.

HUMIDITY AND DEW POINT. CONDENSATION � H2O can exist in solid, liquid, or gaseous states. Change from liquid to gas is evaporation. Change from gas to.

A C M V PSYCHROMETRY (A Review) Dr. Khairul Habib.

1 Refrigeration Technology wu wei-dong Chapter9. Psychrometry and Air Processes.

Department of Mechanical Engineering ME 322 – Mechanical Engineering Thermodynamics Review for Final Exam See also: Exam 1 prep Exam 2 prep Exam 3 prep.

Objectives Describe psychrometric quantities Given any two psychrometric quantities, calculate any other quantity Use Tables A4 or psychrometric charts.

PSYCHROMETRY AND HVAC Psychrometry (hygrometry): science of moist air

Introduction to Energy Management. Week/Lesson 5 Psychrometrics: The Properties of Air.

Moisture in the Atmosphere Beaker demo. Humidity Humidity - how much moisture is in the air. Saturated air is air that is full of water. Dew point is.

Objectives Psychometrics Psychometrics of AHU.

HUMIDITY AND AIR CONDITIONING

Announcements Tonight ASHRAE Student Chapter Meeting.

CHAPTER 13 Gas – Vapor Mixtures and Air-Conditioning.

Chapter 13A: PSYCHROMETRIC PROPERTIES

Psychrometric Chart (or Humidity Chart)

Doug Jefferson, Business Development Engineer

SNS COLLEGE OF ENGINEERING Coimbatore-107 Subject: Thermal Engineering

Course Name: Psychrometry Basics Prof. A. D. Kale

Refrigeration and Air conditioning

Chapter 14 Gas-Vapor Mixtures and Air-Conditioning Study Guide in PowerPoint to accompany Thermodynamics: An Engineering Approach, 8th edition.

Introduction to Food Engineering

PSYCHOMETRICS INTRODUCTION INDEXES PSYCHOMETRIC CHART INTRODUCTION:  PSYCHOMETRICS IS THE STUDY OF MOIST AIR.  THE PSYCHOMETRIC CHART IS A GRAPHIC REPRESENTATION.

PSYCHROMETRY AND HVAC Psychrometry (hygrometry): science of moist air HVAC: Heating, ventilating, and air-conditioning I am teaching Engineering Thermodynamics.

Psychrometric Processes

Chapter 13A: PSYCHROMETRIC PROPERTIES

Objectives Psychometrics Psychometric chart Examples in AHUs.

Objectives Plot processes in AHU and buildings on Psychrometric chart

Objectives Plot processes in AHU and buildings on psychrometric chart

Lecture Objectives: Finish cooling / heat pump example

HW1 Errors Equation for Ra number in handouts Equation for Nu in book.

Lecture Objectives: Learn about air-conditioning (psychrometric)

Objectives Air mixing and humidifying

Lecture 34 The Psychrometric Chart Psychrometric Properties in EES

Psychrometric analysis Revision of principles - Central plant

Lecture Objectives Review what we learned about Eclectic Energy Production Learn about Thermal Comfort Introduce Psychrometric Chart.

Lecture Objectives Learn about Psychrometric Chart Quantities

Objectives Learn more about Psychrometrics

Objectives Continue with Psychometrics Psychometric chart Equations

Objectives Psychometrics Psychometric chart Examples in AHUs.

Presentation transcript:

Engineering Fundamentals：part I Related to moist air and water Thermodynamic properties of moist air State Process Pad and Fan system Pad efficiency at various facing velocity Pad efficiency and pressure drop at various thickness Fan curves Efficiency of the nozzle in misting/fogging system Psychrometric related Tables generated by Psychart software

Thermodynamic properties of moist air dry bulb T wet bulb T dew point T relative humidity absolute humidity (humidity ratio) specific volume enthalpy vapor pressure saturated vapor pressure

With 2 independent properties and the given atmospheric pressure The state of the moist air can be defined.

Psychrometric Chart

Independent Properties Twb rh Tdp AH SV H Pws hfg Pv Tdb P I

Digital Psychrometric Chart

Zoom in & Zoom out

Process: between states Sensible Heating (3->4) Sensible Cooling (4->3) Humidification (4->5) Dehumidification (5->4) Heating (3->5, 3->1) Cooling (5->3, 1->3) Air Mixing (1, 2->3) Evaporative Cooling，Drying (1->2, 1->3) Combination of above (1->2->3->4->5)

A process with sensible heat gain

Move along prefix lines & Curves Constant Twb Constant RH Constant Tdp, Pw, AH Constant Tdp, Pw, AH Constant RH Constant Twb

Efficiency of a Pad and Fan system

Pad efficiency at various facing velocity Eff = 86.62 – 20.787 * V + 2.755 * V2 Kool-Cel pad Eff = 91.034 – 17.91 * V + 5.231 * V2 CELdek pad Eff = 76.055 + 2.909 * V – 17.414 * V2 Excelsior pad Trumbull, et al. (1986) Thickness of the pads were not mentioned. 10 cm ?

Pad efficiency at various facing velocity and thickness 10 cm pad 20 cm pad

Pressure drop at various facing velocity and pad thickness 10 cm pad 20 cm pad

Fan curves of various models of

Blow-off of water from the pad at 1 m/s for the Excelsior pad, at 1.6 m/s for the Kool-Cel pad and at 2 m/s for the CELdek pad Trumbull, et al. (1986)

Efficiency of nozzle (misting/fogging system) β = 0.124 + 1.35 * 10-4 * P Bottcher et al. (1991) P = 64.888 ATM  β= 100% Considering some head loss and friction loss, 70 ATM (70 kg/cm2) was used in my research.

Handy Tables

User friendly 3-step design in PsyTable 1.Define the ranges 2.Set the intervals 3.list the values

Twb = f(Tdb, RH) Twb RH (50 – 100%)and Tdb (20 – 44 oC)

RH = f(Tdb,Twb) RH Twb (20 – 44 oC) and Tdb (20 – 44 oC)

Wet Bulb Depression is the limit of evaporative cooling methods. WBD = f(Tdb,RH) WBD Wet Bulb Depression is the limit of evaporative cooling methods.

Evaporative cooling Methods Pad and Fan system Spraying Misting Fogging Multi-Net Fogging and Fan system