Analysis of Heat Transfer in Air Cooled Condensers
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Vapour Absorption Refrigeration Systems Based on Ammonia- Water Pair
Lesson 17 Vapour Absorption Refrigeration Systems Based On Ammonia- Water Pair Version 1 ME, IIT Kharagpur 1 The specific objectives of this lesson are to: 1. Introduce ammonia-water systems (Section 17.1) 2. Explain the working principle of vapour absorption refrigeration systems based on ammonia-water (Section 17.2) 3. Explain the principle of rectification column and dephlegmator (Section 17.3) 4. Present the steady flow analysis of ammonia-water systems (Section 17.4) 5. Discuss the working principle of pumpless absorption refrigeration systems (Section 17.5) 6. Discuss briefly solar energy based sorption refrigeration systems (Section 17.6) 7. Compare compression systems with absorption systems (Section 17.7) At the end of the lecture, the student should be able to: 1. Draw the schematic of a ammonia-water based vapour absorption refrigeration system and explain its working principle 2. Explain the principle of rectification column and dephlegmator using temperature-concentration diagrams 3. Carry out steady flow analysis of absorption systems based on ammonia- water 4. Explain the working principle of Platen-Munter’s system 5. List solar energy driven sorption refrigeration systems 6. Compare vapour compression systems with vapour absorption systems 17.1. Introduction Vapour absorption refrigeration system based on ammonia-water is one of the oldest refrigeration systems. As mentioned earlier, in this system ammonia is used as refrigerant and water is used as absorbent. Since the boiling point temperature difference between ammonia and water is not very high, both ammonia and water are generated from the solution in the generator. Since presence of large amount of water in refrigerant circuit is detrimental to system performance, rectification of the generated vapour is carried out using a rectification column and a dephlegmator. -
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. -
A Comparative Energy and Economic Analysis Between a Low Enthalpy Geothermal Design and Gas, Diesel and Biomass Technologies for a HVAC System Installed in an Office Building
energies Article A Comparative Energy and Economic Analysis between a Low Enthalpy Geothermal Design and Gas, Diesel and Biomass Technologies for a HVAC System Installed in an Office Building José Ignacio Villarino 1, Alberto Villarino 1,* , I. de Arteaga 2 , Roberto Quinteros 2 and Alejandro Alañón 1 1 Department of Construction and Agronomy, Construction Engineering Area, High Polytechnic School of Ávila, University of Salamanca, Hornos Caleros, 50, 05003 Ávila, Spain; [email protected] (J.I.V.); [email protected] (A.A.) 2 Facultad de Ingeniería, Escuela de Ingeniería Mecánica, Pontificia Universidad Católica de Valparaíso, Av. Los Carrera 01567, Quilpué 2430000, Chile; [email protected] (I.d.A.); [email protected] (R.Q.) * Correspondence: [email protected]; Tel.: +34-920-353-500; Fax: +34-920-353-501 Received: 3 January 2019; Accepted: 25 February 2019; Published: 6 March 2019 Abstract: This paper presents an analysis of economic and energy between a ground-coupled heat pump system and other available technologies, such as natural gas, biomass, and diesel, providing heating, ventilation, and air conditioning to an office building. All the proposed systems are capable of reaching temperatures of 22 ◦C/25 ◦C in heating and cooling modes. EnergyPlus software was used to develop a simulation model and carry out the validation process. The first objective of the paper is the validation of the numerical model developed in EnergyPlus with the experimental results collected from the monitored building to evaluate the system in other operating conditions and to compare it with other available technologies. The second aim of the study is the assessment of the position of the low enthalpy geothermal system proposed versus the rest of the systems, from energy, economic, and environmental aspects. -
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. -
Cryogenicscryogenics Forfor Particleparticle Acceleratorsaccelerators Ph
CryogenicsCryogenics forfor particleparticle acceleratorsaccelerators Ph. Lebrun CAS Course in General Accelerator Physics Divonne-les-Bains, 23-27 February 2009 Contents • Low temperatures and liquefied gases • Cryogenics in accelerators • Properties of fluids • Heat transfer & thermal insulation • Cryogenic distribution & cooling schemes • Refrigeration & liquefaction Contents • Low temperatures and liquefied gases ••• CryogenicsCryogenicsCryogenics ininin acceleratorsacceleratorsaccelerators ••• PropertiesPropertiesProperties ofofof fluidsfluidsfluids ••• HeatHeatHeat transfertransfertransfer &&& thermalthermalthermal insulationinsulationinsulation ••• CryogenicCryogenicCryogenic distributiondistributiondistribution &&& coolingcoolingcooling schemesschemesschemes ••• RefrigerationRefrigerationRefrigeration &&& liquefactionliquefactionliquefaction • cryogenics, that branch of physics which deals with the production of very low temperatures and their effects on matter Oxford English Dictionary 2nd edition, Oxford University Press (1989) • cryogenics, the science and technology of temperatures below 120 K New International Dictionary of Refrigeration 3rd edition, IIF-IIR Paris (1975) Characteristic temperatures of cryogens Triple point Normal boiling Critical Cryogen [K] point [K] point [K] Methane 90.7 111.6 190.5 Oxygen 54.4 90.2 154.6 Argon 83.8 87.3 150.9 Nitrogen 63.1 77.3 126.2 Neon 24.6 27.1 44.4 Hydrogen 13.8 20.4 33.2 Helium 2.2 (*) 4.2 5.2 (*): λ Point Densification, liquefaction & separation of gases LNG Rocket fuels LIN & LOX 130 000 m3 LNG carrier with double hull Ariane 5 25 t LHY, 130 t LOX Air separation by cryogenic distillation Up to 4500 t/day LOX What is a low temperature? • The entropy of a thermodynamical system in a macrostate corresponding to a multiplicity W of microstates is S = kB ln W • Adding reversibly heat dQ to the system results in a change of its entropy dS with a proportionality factor T T = dQ/dS ⇒ high temperature: heating produces small entropy change ⇒ low temperature: heating produces large entropy change L. -
Matching Energy Consumption and Photovoltaic Production in a Retrofitted Dwelling in Subtropical Climate Without a Backup System
energies Article Matching Energy Consumption and Photovoltaic Production in a Retrofitted Dwelling in Subtropical Climate without a Backup System Sergio Gómez Melgar 1,* , Antonio Sánchez Cordero 2 , Marta Videras Rodríguez 2 and José Manuel Andújar Márquez 1 1 TEP192 Control y Robótica, Escuela Técnica Superior de Ingeniería, Universidad de Huelva, CP. 21007 Huelva, Spain; [email protected] 2 Programa de Ciencia y Tecnología Industrial y Ambiental, Escuela Técnica Superior de Ingeniería, Universidad de Huelva, CP. 21007 Huelva, Spain; [email protected] (A.S.C.); [email protected] (M.V.R.) * Correspondence: [email protected] Received: 4 October 2020; Accepted: 16 November 2020; Published: 18 November 2020 Abstract: The construction sector is a great contributor to global warming both in new and existing buildings. Minimum energy buildings (MEBs) demand as little energy as possible, with an optimized architectural design, which includes passive solutions. In addition, these buildings consume as low energy as possible introducing efficient facilities. Finally, they produce renewable energy on-site to become zero energy buildings (ZEBs) or even plus zero energy buildings (+ZEB). In this paper, a deep analysis of the energy use and renewable energy production of a social dwelling was carried out based on data measurements. Unfortunately, in residential buildings, most renewable energy production occurs at a different time than energy demand. Furthermore, energy storage batteries for these facilities are expensive and require significant maintenance. The present research proposes a strategy, which involves rescheduling energy demand by changing the habits of the occupants in terms of domestic hot water (DHW) consumption, cooking, and washing. -
Installation, Setup & Troubleshooting Supplement
EconoMi$er X F a c t o r y --- I n s t a l l e d O p t i o n Low Leak Economizer for 2 Speed SAV (Staged Air Volume) Systems Installation, Setup & Troubleshooting Supplement This document is a supplemental installation instruction for the factory-installed EconoMi$er X (low leak economizer) option. It is to be used with the base unit Installation Instructions for 48/50TC, 50TCQ, 48/50HC, and 50HCQ 2-Stage cooling units, sizes 08 – 30. Units equipped with the EconoMi$er X option are identified by an indicator in the unit's model number (see the unit's nameplate). Use Table 1 (on page 2) to identify whether or not a given unit is equipped with the factory-installed EconoMi$er X. NOTE: Read the entire instruction manual before starting the installation. TABLE OF CONTENTS SAFETY CONSIDERATIONS SAFETY CONSIDERATIONS.................... 1 Improper installation, adjustment, alteration, service, maintenance, or use can cause explosion, fire, electrical GENERAL.................................... 2 shock or other conditions which may cause personal injury Identifying Factory Option...................... 2 or property damage. Consult a qualified installer, service EconoMi$er X................................ 3 agency, or your distributor or branch for information or assistance. The qualified installer or agency must use W7220 Economizer Controller................... 3 factory--authorized kits or accessories when modifying this User Interface................................ 3 product. Refer to the individual instructions packaged with Menu Structure............................... 3 the kits or accessories when installing. Checkout Tests............................... 7 Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloths for brazing operations and SETUP AND CONFIGURATION................ -
Thermodynamics the Study of the Transformations of Energy from One Form Into Another
Thermodynamics the study of the transformations of energy from one form into another First Law: Heat and Work are both forms of Energy. in any process, Energy can be changed from one form to another (including heat and work), but it is never created or distroyed: Conservation of Energy Second Law: Entropy is a measure of disorder; Entropy of an isolated system Increases in any spontaneous process. OR This law also predicts that the entropy of an isolated system always increases with time. Third Law: The entropy of a perfect crystal approaches zero as temperature approaches absolute zero. ©2010, 2008, 2005, 2002 by P. W. Atkins and L. L. Jones ©2010, 2008, 2005, 2002 by P. W. Atkins and L. L. Jones A Molecular Interlude: Internal Energy, U, from translation, rotation, vibration •Utranslation = 3/2 × nRT •Urotation = nRT (for linear molecules) or •Urotation = 3/2 × nRT (for nonlinear molecules) •At room temperature, the vibrational contribution is small (it is of course zero for monatomic gas at any temperature). At some high temperature, it is (3N-5)nR for linear and (3N-6)nR for nolinear molecules (N = number of atoms in the molecule. Enthalpy H = U + PV Enthalpy is a state function and at constant pressure: ∆H = ∆U + P∆V and ∆H = q At constant pressure, the change in enthalpy is equal to the heat released or absorbed by the system. Exothermic: ∆H < 0 Endothermic: ∆H > 0 Thermoneutral: ∆H = 0 Enthalpy of Physical Changes For phase transfers at constant pressure Vaporization: ∆Hvap = Hvapor – Hliquid Melting (fusion): ∆Hfus = Hliquid – -
The Gold Standard in Fan Heaters
WALL FAN HEATER ARWF SERIES THE GOLD STANDARD IN FAN HEATERS The PULSAIR™ is extremely popular for many reasons. First, it can be recessed or surface mounted with a surface adapter (optional). In addition, it can be mounted vertically or horizontally, directing the air flow upward or downward and to the right or to the left, respectively. Last, the slim-line PULSAIR™ can be recessed into W W W W Y Y Y A A A A T T a wall thickness of 2 in. to 3 in. While it’s a winning heating solu- T R R R R N N N R R R R A A A LIFETIME A A A A R R R N N N N R R R on element T T T T A A A tion for the hallway and bathroom, it can also be installed in other Y Y Y Y W W W W W W parts of the house, such as the office or in commercial buildings. W Y Y Y Y A A A A T T T T R R R R N N N R N Its nichrome element provides instant heat. Available from 500 W R A R A R A A A A R A R A R R N N N N 2YEAR R 3YEAR R 5YEAR R 5YEAR R T A T A T A T to 2000 W, and from 120 V to 277 V, the PULSAIR™ is recognized Y Y Y Y A W W W W W W W W and recommended by those in the know. -
Single Pole Humidity Sensor and Fan Controller Cat
Single Pole Humidity Sensor and Fan Controller Cat. Nos. IPHS5 - INDOOR USE ONLY 120VAC, 60Hz - Single Pole Only Incandescent: 600W - MLV/Fluorescent: 400VA - LED/CFL: 150W - Fan: 1/6Hp WARNINGS CAUTIONS • TO AVOID FIRE, SHOCK OR DEATH: TURN OFF POWER AT CIRCUIT BREAKER • Clean outer surface gently with damp cloth only. DO NOT use soaps or cleaning OR FUSE AND TEST THAT THE POWER IS OFF BEFORE WIRING! liquids. • TO AVOID PERSONAL INJURY OR PROPERTY DAMAGE, DO NOT install to • No user serviceable components. DO NOT attempt to service or repair. control a receptacle, or a load in excess of the specified rating. • Use this device WITH COPPER CLAD WIRE ONLY. • To be installed and/or used in accordance with electrical codes and regulations. • If you are not sure about any part of these instructions, consult an electrician. DI-000-IPHS5-02B INSTALLATION ENGLISH Features Location You Will Need: The humidity sensor and fan controller senses the humidity of your bathroom • Slotted/Phillips screwdriver • For bathroom applications the device should be placed and turns your bath fan or fan/light on when the humidity gets too high, • Pencil reducing condensation in your bathroom and increasing ventilation when used at a level to detect steam. Placing the detector directly in other household spaces. above a heater or near drafts is not recommended. • Electrical tape • Compatible with Incandescent, LED, CFL and Fluorescent loads when • NOTE: DO NOT use to control a fan/light combination • Cutters used with combination fan and light fixtures. where the fan/light is the only means of illumination. -
Delta Fan Heater
PAGE 1/2 DELTA FAN HEATER DELTA is a robust, reliable fan heater that is designed for use in TECHNICAL DATA areas that require a little more of materials and performance, for Voltage range: instance construction sites and ships. • 1x110V to 3x690V + PE DELTA is also used for more permanent installations such as in- Frequenzy, can be used at: dustrial buildings and warehouses, workshops, factories or ga- • 50 Hz and 60 Hz rages, as it can go from transportable to permanent fixture with Degree of protection for electrical components: a simple wall-bracket. • TP1: 3-9kW = IP44 • TP2: 15-21kW = IP34 It comes with an integrated 0-40°C room thermostat that en- Temperature control: sures optimal operation and minimizes energy consumption, as • TP1: Combi termostat with adjustable room thermostat 0-40°C well as a thermal cut-out to protect against overheating. The + thermal cut-out fan heater works without standby and does not use unneces- • TP2: Adjustable room thermostat 0-40°C + thermal cut-out sary power. Level regulation: • Manually operated 5-level change-over switch that regulates DELTA is built with internal casing in the heating chamber, which air speed and heating effect. Moreover, all types can be sup- ensures that the entire flow of air passes over the heating ele- plied with a 24-hour timer. A DELTA fan heater with timer ments. This eliminates problems with varying airflow and cold function switches on when the set time has elapsed. spots. Off The DELTA fan heater comes in two sizes: • TP1 = 3-9 kW - small cabinet Fan on • TP2 = 15-21 kW - large cabinet Half fan and half heat effect TP1: 372 mm TP1: 300 mm TP2: 462 mm TP2: 360 mm Full fan and half heat effect Full fan and full heat effect TP1: 435 mm TP2: 540 mm TP1: 322 mm ELECTRICAL INSTALLATION TP2: 392 mm Permanent installation must always be performed by an authori- zed electrician in accordance with relevant laws and regulations. -
Airflow Measuring System Using Piezometer Ring – IM-105
IM-105 Piezometer Ring June 2021 Installation, Operation & Maintenance Manual REVIEW AMCA BULLETIN 410 PRIOR TO INSTALLATION This manual has been prepared to guide the users of an airflow measuring system using a piezometer ring in the proper installation, operation and maintenance procedures to ensure maximum equipment life with trouble-free operation. For safe installation, startup and operational life of this equipment, it is important that all involved with the equipment be well versed in proper fan safety practices and read this manual. It is the user’s responsibility to make sure that all requirements of good safety practices and any applicable safety codes are strictly adhered to. Because of the wide variety of equipment covered in this manual, the instructions given here are general in nature. Additional product and engineering information is available at www.tcf.com. SAFETY NOTICE Refer to the safety section(s) in this manual prior to installing or servicing the fan. The most current version of this installation and maintenance manual can be found on our website at www.tcf.com/resources/im-manuals. Table of Contents Safety & Hazard Warnings ...........................................................................................................................................................................2 Shipping & Receiving ....................................................................................................................................................................................2 Handling ......................................................................................................................................................................................................