The Humidity/Moisture Handbook
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Chapter 5 Measures of Humidity Phases of Water
Chapter 5 Atmospheric Moisture Measures of Humidity 1. Absolute humidity 2. Specific humidity 3. Actual vapor pressure 4. Saturation vapor pressure 5. Relative humidity 6. Dew point Phases of Water Water Vapor n o su ti b ra li o n m p io d a a at ep t v s o io e en s n d it n io o n c freezing Liquid Water Ice melting 1 Coexistence of Water & Vapor • Even below the boiling point, some water molecules leave the liquid (evaporation). • Similarly, some water molecules from the air enter the liquid (condense). • The behavior happens over ice too (sublimation and condensation). Saturation • If we cap the air over the water, then more and more water molecules will enter the air until saturation is reached. • At saturation there is a balance between the number of water molecules leaving the liquid and entering it. • Saturation can occur over ice too. Hydrologic Cycle 2 Air Parcel • Enclose a volume of air in an imaginary thin elastic container, which we will call an air parcel. • It contains oxygen, nitrogen, water vapor, and other molecules in the air. 1. Absolute Humidity Mass of water vapor Absolute humidity = Volume of air The absolute humidity changes with the volume of the parcel, which can change with temperature or pressure. 2. Specific Humidity Mass of water vapor Specific humidity = Total mass of air The specific humidity does not change with parcel volume. 3 Specific Humidity vs. Latitude • The highest specific humidities are observed in the tropics and the lowest values in the polar regions. -
Heat Generation Technology Landscaping Study, Scotland's
Heat Generation Technology Landscaping Study, Scotland’s Energy Efficiency Programme (SEEP) BRE August 2017 Summary This landscaping study has reviewed the status and suitability of a number of near-term heat generation technologies that are not already significantly established in the market-place. The study has been conducted to inform Scottish Government on the status and the technologies so that they can make informed decisions on the potential suitability of the technologies for inclusion within Scotland’s Energy Efficiency Programme (SEEP). Some key findings which have emerged from the research include: • High temperature, hybrid and gas driven heat pumps all have the potential to increase the uptake of low carbon heating solutions in the UK in the short to medium term. • High temperature heat pumps are particularly suited for off-gas grid retrofit projects, whereas hybrids and gas driven products are suited to on-gas grid properties. They may all be used with no or limited upgrades to existing heating systems, and each offers some advantages (but also some disadvantages) compared with standard electric heat pumps. • District heating may continue to have a significant role to play – albeit more on 3rd and 4th generation systems than the large high temperature systems typical in other parts of Europe in the 1950s and 60s – due to lower heating requirements of modern retrofitted buildings. • Longer term, the development of low carbon heating fuel markets may also present significant opportunity e.g. biogas, and possibly hydrogen. -
5Th-Generation Thermox WDG Flue Gas Combustion Analyzer
CONTROL EXCLUSIVE 5th-Generation Thermox WDG Flue Gas Combustion Analyzer “For more than 40 years, we have been a leader in combustion gas analysis,” says Mike Fuller, divison VP of sales and marketing and business development for Ametek Process Instruments, “and we believe the WDG-V is the combustion analyzer of the future.” WDG analyzers are based on a zirconium oxide cell that provides a reliable and cost-effective solution for measuring excess oxygen in flue gas as well as CO and methane levels. This information allows operators to obtain the highest fuel effi- ciency, while lowering emissions for NOx, CO and CO2. The zir- conium oxide cell responds to the difference between the concen- tration of oxygen in the flue gas versus an air reference. To assure complete combustion, the flue gas should contain several percent oxygen. The optimum excess oxygen concentration is dependent on the fuel type (natural gas, hydrocarbon liquids and coal). The WDG-V mounts directly to the process flange, and is heated to maintain all sample-wetted components above the acid dewpoint. Its air-operated aspirator draws a sample into the ana- lyzer and returns it to the process. A portion of the sample rises into the convection loop past the combustibles and oxygen cells, Ametek’s WDG-V flue gas combustion analyzer meets SIL-2 and then back into the process. standards for safety instrumented systems. This design gives a very fast response and is perfect for process heat- ers. It features a reduced-drift, hot-wire catalytic detector that is resis- analyzer with analog/HART, discrete and Modbus RS-485 bi-direc- tant to sulfur dioxide (SO ) degradation, and the instrument is suitable 2 tional communications, or supplied in a typical “sensor/controller” for process streams up to 3200 ºF (1760 ºC). -
Insar Water Vapor Data Assimilation Into Mesoscale Model
This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING 1 InSAR Water Vapor Data Assimilation into Mesoscale Model MM5: Technique and Pilot Study Emanuela Pichelli, Rossella Ferretti, Domenico Cimini, Giulia Panegrossi, Daniele Perissin, Nazzareno Pierdicca, Senior Member, IEEE, Fabio Rocca, and Bjorn Rommen Abstract—In this study, a technique developed to retrieve inte- an extremely important element of the atmosphere because its grated water vapor from interferometric synthetic aperture radar distribution is related to clouds, precipitation formation, and it (InSAR) data is described, and a three-dimensional variational represents a large proportion of the energy budget in the atmo- assimilation experiment of the retrieved precipitable water vapor into the mesoscale weather prediction model MM5 is carried out. sphere. Its representation inside numerical weather prediction The InSAR measurements were available in the framework of the (NWP) models is critical to improve the weather forecast. It is European Space Agency (ESA) project for the “Mitigation of elec- also very challenging because water vapor is involved in pro- tromagnetic transmission errors induced by atmospheric water cesses over a wide range of spatial and temporal scales. An vapor effects” (METAWAVE), whose goal was to analyze and pos- improvement in atmospheric water vapor monitoring that can sibly predict the phase delay induced by atmospheric water vapor on the spaceborne radar signal. The impact of the assimilation on be assimilated in NWP models would improve the forecast the model forecast is investigated in terms of temperature, water accuracy of precipitation and severe weather [1], [3]. -
Air Pressure
Name ____________________________________ Date __________ Class ___________________ SECTION 15-3 SECTION SUMMARY Air Pressure Guide for ir consists of atoms and molecules that have mass. Therefore, air has Reading A mass. Because air has mass, it also has other properties, includ- ing density and pressure. The amount of mass per unit volume of a N What are some of substance is called the density of the substance. The force per unit area the properties of air? is called pressure. Air pressure is the result of the weight of a column of N What instruments air pushing down on an area. The molecules in air push in all directions. are used to mea- This is why air pressure doesn’t crush objects. sure air pressure? Falling air pressure usually indicates that a storm is approaching. Rising N How does increas- air pressure usually means that the weather is clearing. A ing altitude affect barometer is an instrument that measures changes in air pressure. There air pressure and are two kinds of barometers: mercury barometers and aneroid density? barometers. A mercury barometer consists of a glass tube open at the bottom end and partially filled with mercury. The open end of the tube rests in a dish of mercury, and the space above the mercury in the tube contains no air. The air pressure pushing down on the surface of the mer- cury in the dish is equal to the weight of the column of mercury in the tube. At sea level, the mercury column is about 76 centimeters high, on average. An aneroid barometer has an airtight metal chamber that is sen- sitive to changes in air pressure. -
Humidity in Gas-Fired Kilns Proportion of Excess Combustion
HUMIDITY OF COMBUSTION PRODUCTS FROM WOOD AND GASEOUS FUELS George Bramhall Western Forest Products Laboratory Vancouver, British Columbia The capital and operating costs of steam kilns and the boilers necessary for their operation are so high-in Canada that they are not economically feasible for small operations drying softwoods. About thirty years ago, direct fired or hot-air kilns were intro- duced. In such kilns natural gas, propane, butane or oil is burned and the combustion products conducted directly into the drying chamber. This design eliminates the high capital and operating costs of the steam boiler, and permits the small operator to dry lumber economically. However, such kilns are not as versatile as steam kilns. While they permit good temperature control, their humidity control is limited: they can only reduce excess humidity by venting, they cannot increase it and therefore cannot relieve drying stresses at the end of drying. For this reason, they are usually limited to the drying of structural lumber. Due to the decreasing supplies and increasing costs of fossil fuels, there is growing interest in burning wood residues to pro- vide the heat for drying. Although wood residue was often the fuel for steam boilers, the capital and operating costs of boilers are no more acceptable now to the smaller operator than they were a few years ago. The present trend is rather to burn wood cleanly and conduct the combustion products into the kiln in the same man- ner as is done with gaseous fossil fuels. This is now being done successfully with at least one type of burner, and others are in the pilot stage. -
Effect of Tropospheric Air Density and Dew Point Temperature on Radio (Electromagnetic) Waves and Air Radio Wave Refractivity
International Journal of Scientific & Engineering Research, Volume 7, Issue 6, June-2016 356 ISSN 2229-5518 Effect of Tropospheric Air density and dew point temperature on Radio (Electromagnetic) waves and Air radio wave refractivity <Joseph Amajama> University of Calabar, Department of Physics, Electronics and Computer Technology Unit Etta-agbor, Calabar, Nigeria [email protected] Abstract: Signal strengths measurements were obtained half hourly for some hours and simultaneously, the atmospheric components: atmospheric temperature, atmospheric pressure, relative humidity and wind direction and speed were registered to erect the effects of air density and dew point temperature on radio signals (electromagnetic waves) as they travel through the atmosphere and air radio wave refractivity. The signal strength from Cross River State Broadcasting Co-operation Television (CRBC-TV), (4057'54.7''N, 8019'43.7''E) transmitted at 35mdB and 519.25 MHz (UHF) were measured using a Cable TV analyzer in a residence along Ettaabgor, Calabar, Nigeria (4057'31.7''N, 8020'49.7''E) using the digital Community – Access (Cable) Television (CATV) analyzer with 24 channels, spectrum 46 – 870 MHz, connected to a domestic receiver antenna of height 4.23 m. Results show that: on the condition that the wind speed and direction are the same or (0 mph NA), the radio signal strength is near negligibly directly proportional to the air density, mathematically Ss / ∂a1.3029 = K, where Ss is Signal Strength in dB, ∂a is Density of air Kg/m3 and K is constant; radio -
Air Infiltration Glossary (English Edition)
AIRGLOSS: Air Infiltration Glossary (English Edition) Carolyn Allen ~)Copyrlght Oscar Faber Partnership 1981. All property rights, Including copyright ere vested In the Operating Agent (The Oscar Faber Partnership) on behalf of the International Energy Agency. In particular, no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permluion of the operat- ing agent. Contents (i) Preface (iii) Introduction (v) Umr's Guide (v) Glossary Appendix 1 - References 87 Appendix 2 - Tracer Gases 93 Appendix 3 - Abbreviations 99 Appendix 4 - Units 103 (i) (il) Preface International Energy Agency In order to strengthen cooperation In the vital area of energy policy, an Agreement on an International Energy Program was formulated among a number of industrialised countries In November 1974. The International Energy Agency (lEA) was established as an autonomous body within the Organisation for Economic Cooperation and Development (OECD) to administer that agreement. Twenty-one countries are currently members of the lEA, with the Commission of the European Communities participating under a special arrangement. As one element of the International Energy Program, the Participants undertake cooperative activities in energy research, development, and demonstration. A number of new and improved energy technologies which have the potential of making significant contributions to our energy needs were identified for collaborative efforts. The lEA Committee on Energy Research and Development (CRD), assisted by a small Secretariat staff, coordinates the energy research, development, and demonstration programme. Energy Conservation in Buildings and Community Systems The International Energy Agency sponsors research and development in a number of areas related to energy. -
Air Separation, Flue Gas Compression and Purification Units for Oxy-Coal Combustion Systems
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Energy Energy Procedia 4 (2011) 966–971 www.elsevier.com/locate/procediaProcedia Energy Procedia 00 (2010) 000–000 www.elsevier.com/locate/XXX GHGT-10 Air Separation, flue gas compression and purification units for oxy-coal combustion systems Jean-Pierre Traniera, Richard Dubettierb, Arthur Dardeb, Nicolas Perrinc aAir Liquide SA-Centre de Recherche Claude Delorme,Chemin de la porte des Loges, Les Loges en Josas, Jouy en Josas F-78354, France bAir Liquide Engineering, 57 Ave. Carnot BP 313,Champigny-sur-Marne F-94503, France cAir Liquide SA, 57 Ave. Carnot BP 313, Champigny-sur-Marne F-94503, France Elsevier use only: Received date here; revised date here; accepted date here Abstract Air Liquide (AL) has been actively involved in the development of oxy-coal technologies for CO2 capture from power plants for almost 10 years. Large systems for oxygen production and flue gas purification are required for this technology. Air Liquide has been a leader in building large Air Separation Units (ASUs) and more developments have been performed to customize the air separation process for coal-fired power plants. Air Liquide is also actively involved in developing processes for purification of flue gas from oxy-coal combustion systems for enhanced oil recovery applications as well as sequestration in saline aquifers. Through optimization of the overall oxy-coal combustion system, it has been possible to identify key advantages of this solution: minimal efficiency loss associated with CO2 capture (less than 6 pts penalty on HHV efficiency compared to no capture), near zero emission, energy storage, high CO2 purity and high CO2 recovery capability. -
Calculation Exercises with Answers and Solutions
Atmospheric Chemistry and Physics Calculation Exercises Contents Exercise A, chapter 1 - 3 in Jacob …………………………………………………… 2 Exercise B, chapter 4, 6 in Jacob …………………………………………………… 6 Exercise C, chapter 7, 8 in Jacob, OH on aerosols and booklet by Heintzenberg … 11 Exercise D, chapter 9 in Jacob………………………………………………………. 16 Exercise E, chapter 10 in Jacob……………………………………………………… 20 Exercise F, chapter 11 - 13 in Jacob………………………………………………… 24 Answers and solutions …………………………………………………………………. 29 Note that approximately 40% of the written exam deals with calculations. The remainder is about understanding of the theory. Exercises marked with an asterisk (*) are for the most interested students. These exercises are more comprehensive and/or difficult than questions appearing in the written exam. 1 Atmospheric Chemistry and Physics – Exercise A, chap. 1 – 3 Recommended activity before exercise: Try to solve 1:1 – 1:5, 2:1 – 2:2 and 3:1 – 3:2. Summary: Concentration Example Advantage Number density No. molecules/m3, Useful for calculations of reaction kmol/m3 rates in the gas phase Partial pressure Useful measure on the amount of a substance that easily can be converted to mixing ratio Mixing ratio ppmv can mean e.g. Concentration relative to the mole/mole or partial concentration of air molecules. Very pressure/total pressure useful because air is compressible. Ideal gas law: PV = nRT Molar mass: M = m/n Density: ρ = m/V = PM/RT; (from the two equations above) Mixing ratio (vol): Cx = nx/na = Px/Pa ≠ mx/ma Number density: Cvol = nNav/V 26 -1 Avogadro’s -
Don't Let Dollars Disappear up Your Chimney!
ENERGY SAVINGTIPS DON’T LET DOLLARS DISAPPEAR UP YOUR CHIMNEY! You wouldn’t leave a window wide open in cold weather. Having a fireplace with an open flue damper is the same as having a window open. That sends precious winter heat and money right up the chimney! Here’s how you can heat your home, and not the neighborhood! KEEP THE FIREPLACE DAMPER CLOSED WHEN THE FIREPLACE IS NOT BEING USED The damper is a flap inside the chimney or flue. It has an open and a closed position. When a fire is burning, the damper should be in the open position to allow smoke to escape up the fireplace flue and out the chimney. When you’re not using the fireplace, the damper should be closed. If you can’t see the handle or chain that opens and closes the damper, use a flashlight and look up inside the chimney flue. The handle could be a lever that moves side to side or back and forth. If a chain operates the damper, you may have to pull both sides to determine which one closes or opens the damper. KEEP YOUR HEAT IN YOUR HOME! Even the most energy efficient homes can fall victim to fireplace air leaks. Your fireplace may be reserved for a handful of special occasions or especially cold nights. When it’s not in use, though, your home loses heat – and costs you money – without you knowing it. Using the heat from your fireplace on a cold winter night may be cozy, but that fire is a very inefficient way to warm up the room. -
CE-087 Calculation of Gas Density and Viscosity
CE‐087 Calculation of Gas Density and Viscosity Instructor: Harlan Bengtson, PhD, P.E. Course ID: CE‐087 PDH Hours: 2 PDH PDH Star | T / F: (833) PDH‐STAR (734‐7827) | E: [email protected] Calculation of Gas Density and Viscosity Harlan H. Bengtson, PhD, P.E. COURSE CONTENT 1. Introduction The density and/or viscosity of a gas is often needed for some other calculation, such as pipe flow or heat exchanger calculations. This course contains discussion of, and example calculation of, the density and viscosity of a specified gas at a given temperature and pressure. If the gas temperature is high relative to its critical temperature and the gas pressure is low relative to its critical pressure, then it can be treated as an ideal gas and its density can be calculated at a specified temperature and pressure using the ideal gas law. If the density of a gas is needed at a temperature and pressure at which it cannot be treated as an ideal gas law, however, then the compressibility factor of the gas must be calculated and used in calculating its density. In this course, the Redlich Kwong equation will be used for calculation of the compressibility factor of a gas. The Sutherland formula can be used to calculate the viscosity of a gas at a specified temperature and pressure if the Sutherland constants are available for the gas. It will be discussed and used in example calculations. Another method for calculating the viscosity of air at a specified temperature and pressure will also be presented and discussed.