Plate Heat Exchangers for Refrigeration Applications
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Modeling and Optimization of a Thermosiphon for Passive Thermal Management Systems
MODELING AND OPTIMIZATION OF A THERMOSIPHON FOR PASSIVE THERMAL MANAGEMENT SYSTEMS A Thesis Presented to The Academic Faculty by Benjamin Haile Loeffler In Partial Fulfillment of the Requirements for the Degree Master of Science in the G. W. Woodruff School of Mechanical Engineering Georgia Institute of Technology December 2012 MODELING AND OPTIMIZATION OF A THERMOSIPHON FOR PASSIVE THERMAL MANAGEMENT SYSTEMS Approved by: Dr. J. Rhett Mayor, Advisor Dr. Sheldon Jeter G. W. Woodruff School of Mechanical G. W. Woodruff School of Mechanical Engineering Engineering Georgia Institute of Technology Georgia Institute of Technology Dr. Srinivas Garimella G. W. Woodruff School of Mechanical Engineering Georgia Institute of Technology Date Approved: 11/12/2012 ACKNOWLEDGEMENTS I would like to first thank my committee members, Dr. Jeter and Dr. Garimella, for their time and consideration in evaluating this work. Their edits and feedback are much appreciated. I would also like to acknowledge my lab mates for the free exchange and discussion of ideas that has challenged all of us to solve problems in new and better ways. In particular, I am grateful to Sam Glauber, Chad Bednar, and David Judah for their hard work on the pragmatic tasks essential to this project. Andrew Semidey has been a patient and insightful mentor since my final terms as an undergrad. I thank him for his tutelage and advice over the years. Without him I would have remained a mediocre heat transfer student at best. Andrew was truly indispensable to my graduate education. I must also thank Dr. Mayor for his guidance, insight, and enthusiasm over the course of this work. -
The Potential and Challenges of Solar Boosted Heat Pumps for Domestic Hot Water Heating
Solar Calorimetry Laboratory The Potential and Challenges of Solar Boosted Heat Pumps for Domestic Hot Water Heating Stephen Harrison Ph.D., P. Eng., Solar Calorimetry Laboratory, Dept. of Mechanical and Materials Engineering, Queen’s University, Kingston, ON, Canada Solar Calorimetry Laboratory Background • As many groups try to improve energy efficiency in residences, hot water heating loads remain a significant energy demand. • Even in heating-dominated climates, energy use for hot water production represents ~ 20% of a building’s annual energy consumption. • Many jurisdictions are imposing, or considering regulations, specifying higher hot water heating efficiencies. – New EU requirements will effectively require the use of either heat pumps or solar heating systems for domestic hot water production – In the USA, for storage systems above (i.e., 208 L) capacity, similar regulations currently apply Canadian residential sector energy consumption (Source: CBEEDAC) Solar Calorimetry Laboratory Solar and HP water heaters • Both solar-thermal and air-source heat pumps can achieve efficiencies above 100% based on their primary energy consumption. • Both technologies are well developed, but have limitations in many climatic regions. • In particular, colder ambient temperatures lower the performance of these units making them less attractive than alternative, more conventional, water heating approaches. Solar Collector • Another drawback relates to the requirement to have an auxiliary heat source to supplement the solar or heat pump unit, -
Modeling and Simulation of a Thermosiphon Solar Water Heater in Makurdi Using Transient System Simulation
International Journal of Scientific & Engineering Research Volume 10, Issue 12, December-2019 451 ISSN 2229-5518 Modeling and Simulation of a Thermosiphon Solar Water Heater in Makurdi using Transient System Simulation Prof. Joshua Ibrahim, Dr. Aoandona Kwaghger, Engr. Shehu Mohammed Sani ABSTRACT The modeling and simulation of a thermosyphon solar water heater at Makurdi (7.74oN) Nigeria was conducted for a period of three months (November, 2013- January, 2014). The research was aimed at simulating the performance of a solar water heater by using various parameters for greater efficiency. The solar water heater was developed and its performance was simulated at University of Agriculture Makurdi. The solar radiation on a horizontal surface was measured using a solarimeter. The water mass flow rates were measured using a Flow meter. The relative humidity data were measured using the Hygrometer. The inlet, outlet and ambient temperatures were measured using a Digital thermometer. For the simulation of the entire system the following measured parameters were used, as global solar radiation on collector plate, collector ambient temperature, heat exchanger and storage tank ambient temperature, flow rate of the collector and storage loop, the cold tap water temperature and the hot water usage. For the validation of the model and for the identification of parameters as heat loss coefficients in situ measurements were performed. Based on the developed models parameter sensitivity analysis and transient influences can be examining for the element and the entire system as well. The results obtained were simulated using Transient simulation software16 (TRNSYS). The results obtained showed that the daily average solar radiation for the period varied from 405 푊/푚2 to1008 푊/푚2. -
Clean Coil Program
TM CLEAN COIL PROGRAM There are many good reasons to clean coils! And, here is what the Nu-Calgon Clean Coil & IAQ Assurance Program can do for you... Gain significant savings on energy costs. Maintain peak operating efficiency. Enhance the cooling system’s reliability and service life. Prevent costly breakdowns. Improve Indoor Air Quality (IAQ). Backed by Nu-Calgon, the leader in HVAC and Refrigeration maintenance chemicals for more than 60 years. www.nucalgon.com l www.coilcleaning.com l www.coilprotection.com NU-CALGON CLEAN COIL & IAQ ASSURANCE PROGRAM FOR AIR CONDITIONING, REFRIGERATION SYSTEMS Over the last 50 years, Nu-Calgon has developed products that have proven themselves in the successful cleaning and protection of air conditioning and refrigeration equipment. Now, these products have been further developed into a program that will keep this equipment operating efficiently and effectively, thereby cutting electric bills, increasing the equipment’s service life, and improving the comfort and Indoor Air Quality of the building or home. An air conditioning or refrigeration system has two “finned” coils, and typically they are constructed of copper tube and aluminum fins. The evaporator coil is the indoor coil, usually referred to as the “A” coil in residential systems. It could be described as “cold” as it provides indoor cooling by absorbing the heat as a fan passes the building air over it. The condenser coil or outdoor coil is the coil that is “warm” as it rejects the heat as a fan blows outdoor air across it. These coils are sized to match the Btu cooling load or requirement of the home or building, and they are engineered for maximum heat transfer . -
Compact Heat Exchangers for Mobile Co2 Systems
COMPACT HEAT EXCHANGERS FOR MOBILE CO2 SYSTEMS A. Hafner SINTEF Energy Research Refrigeration and Air Conditioning Trondheim (Norway) ABSTRACT The natural refrigerant carbon dioxide (CO2) with all its advantages offers new possibilities of efficient heating and cooling at different climates. In reversible air conditioning systems the capacity and efficiency in cooling mode is seen to be most important. The efficiency of the reversible interior heat exchanger depends on the design of the heat exchanger. Efficiency reduction is among other factors caused by refrigerant- side pressure drop, heat conduction, refrigerant- and air maldistribution. Uniform air temperatures at the outlet of the heat exchanger are an important aspect regarding comfort and control of the mobile HVAC system. A prototype CO2 system with a separator, refrigerant pump and a single pass heat exchanger was tested under varies conditions. The tests were performed at low compressor revolution speed i.e. idle conditions. Compared with a baseline heat exchanger of equal size, the use of an external operated pump to circulate the refrigerant through the heat exchanger, increased the cooling capacity at equal pressure levels by up to 14 %. At equal cooling capacities the COP increased by up to 23 %. Airside temperature distribution was more uniform with this way of operating the system. 1 INTRODUCTION Several authors for example Hrnjak et al 2002, Nekså et al. 2001 describe CO2 systems where flash gas was bypassed the evaporator and thereafter reunified with the leaving gas of the evaporator. With such a system concept only liquid refrigerant enters the evaporator which has an positive effect on distribution of the refrigerant into 20000 the microchannels. -
Indoor Air Quality Products Offering Healthy Home Solutions
Indoor Air Quality Products Offering Healthy Home Solutions Carrier clears the air for enhanced indoor comfort What You Can Expect From Carrier Innovation, efficiency, quality: Our Carrier® Healthy Home Solutions offers superior control over the quality of your indoor air and as a result, improved comfort. From air purification and filtration to humidity control, ventilation and more, these products represent the Carrier quality, environmental stewardship and lasting durability that have endured for more than a century. In 1902, that’s the year a humble but determined engineer solved one of mankind’s most elusive challenges – controlling indoor comfort. A leading engineer of his day, Dr. Willis Carrier would file more than 80 patents over the course of his career. His genius would enable incredible advancements in health care, manufacturing processes, food preservations, art and historical conservation, indoor comfort and much more. Carrier’s foresight changed the world forever and paved the way for over a century of once-impossible innovations. Designed with Your Comfort in Mind Carrier® Healthy Home Solutions represents years of design, development and testing with one goal in mind – maximizing your family’s comfort. Along the way, we have taken the lead with new technologies that deliver the superior performance you demand while staying ahead of industry trends and global initiatives. With innovations like Captures & Kills™ technology and superior humidity and airflow control, whatever your need, Carrier has a solution that’s perfectly tailored for you. 2 Ready to Clear the Air? The EPA has found that indoor levels of many air pollutants are often higher than outdoor levels. -
Heat Exchangers Quick Facts
TM WATER HEATERS Heat Exchangers Quick Facts HUBBELLHEATERS.COM What Are They? A heat exchanger is a device that allows thermal energy (heat) from a liquid or gas to pass another fluid without the two fluids mixing. It transfers the heat without transferring the fluid that carries the heat. Therefore, just the heat is exchanged from one fluid to another. This type of heat transfer is utilized with many applications including water heating, sewage treatment, heating and air conditioning, and refrigera- tion. There are several different types of heat exchangers, each with their own design that work to heat up water. Next we will break down some of the key features of commonly used heat exchangers and the differences between them. Plate: A plate heat exchanger consists of a series of metal plates, typically stainless steel, that are joined together with a small amount of space between the face of the plates. The bottom of the plates create a small gutter or channel in between each plate which helps to keep water flowing. The thinner the channel, the more efficient the plates will be at transferring heat to the water because smaller amounts of water can be heated up faster. Plate heat exchangers have a large surface area, so as fluid flows in between these plates, it extracts heat from the plates rather quickly. This design is available as a brazed plate or gasketed design and can be configured as single or double wall. www.hubbellheaters.com Page 1 Electric/Coil: An electric heat exchanger is probably what most people think of when they think “electric heat” It is a simple coil wire that gives off heat like a light bulb in a lamp, and when electricity flows through it, it converts the energy passing through into heat. -
Solar Water Heating System Requirements
Solar Water Heating Installation Requirements Adapted from The Bright Way to Heat Water™ technical requirements V 27 Energy Trust of Oregon Solar Water Heating Installation Requirements Revisions Energy Trust updates these installation requirements annually. Many thanks to the industry members and technical specialists that have invested their time to help keep this document current. The current document (v 27) underwent significant changes from previous installation requirements. Much of the redundant commentary material was removed and many requirements were evaluated based on cost effectiveness and removed or relaxed. The revisions table below summarizes many of the new changes however this document should be read in its entirety to understand the changes. August, 2012 Revisions Section Revision 2.2 Changed requirement for avoiding galvanic action, allowing aluminum Materials to galvanized steel connections. Requirements related to overheat and freeze protection were moved 2.3 to the new Solar Water Heating System Design and Eligibility Equipment and Installation Requirements document. Water quality requirements were removed. Requirements related to heat exchanger materials were moved to the 2.6 new Solar Water Heating System Design and Eligibility Requirements Plumbing document. Parts of Section 2.10 from v 26 were integrated into section 2.6. Backup water heater requirements were removed and/or deferred to code. 2.8 Anti-convective piping requirements were removed. Backup Water Heater Backup water heater R-10 floor pad was removed. Parts of Section 2.10 from v 26 were integrated into section 2.8 2.9 Storage to collector ratios were revised for single tank systems and moved to the new Solar Water Heating System Design and Eligibility Solar Storage Tank Requirements document. -
Cooling Towers and Condenser Water Systems Design and Operation
a Trane Engineers Newsletter Live Cooling Towers and Condenser Water Systems: Design and Operation • 2005 Cooling Towers and Condenser Water Systems Design and Operation an Engineers Newsletter Live telecast © 2005 American Standard Inc. Today’s Topics Fundamentals Chiller–tower interaction Cooling-tower terminology, operation Design conditions Cooling-tower control options System optimization © 2005 Standard Inc. American Answers to your questions © 2018 Trane a business of Ingersoll Rand. All rights reserved Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any 1 resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional. a Trane Engineers Newsletter Live Cooling Towers and Condenser Water Systems: Design and Operation • 2005 Today’s Presenters Dave Mick Lee Cline © 2005 Standard Inc. American Guckelberger Schwedler systems applications applications marketing engineer engineer engineer Cooling Towers and Condenser Water Systems Design and Operation Cooling tower fundamentals © 2005 American Standard Inc. © 2018 Trane a business of Ingersoll Rand. All rights reserved Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any 2 resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional. a Trane Engineers Newsletter Live Cooling Towers and Condenser Water Systems: Design and Operation • 2005 Refrigeration Cycle 2-stage compressor evaporator condenser economizer © 2005 Standard Inc. American expansion expansion device device Pressure–Enthalpy (p-h) Chart subcooled liquid liquid + vapor mix superheated pressure A B vapor 5 psia © 2005 Standard Inc. American 15.5 Btu/lb enthalpy 92.4 Btu/lb © 2018 Trane a business of Ingersoll Rand. -
Compressor Cooling
Compressor cooling Compressed air – the fourth utility A gas compressor is a mechanical compressed air are pneumatic tools, The major cooling applications for device that converts power into kinetic energy storage, production lines, compressors where heat exchangers energy by increasing the pressure of automated assembly stations, are used are: gas and reducing its volume. refrigeration, gas dusters and air-start • Air cooling systems. • Oil cooling Compressed air has become one of • Water cooling the most important power media used Another important power media is • Heat recovery in industry providing power for a compressed natural gas (CNG), which multitude of manufacturing operations. is made by compressing natural gas to In industry, compressed air is so widely less than 1% of the volume it occupies used that it is often regarded as the at standard atmospheric pressure. fourth utility, after electricity, natural gas CNG is generally used in traditional and water. General uses of combustion engines. Oil-free Compressor Oil Air Water Air cooling The compressed gas from the Oil cooling A multi-stage compressor can contain compressor is hot after compression, Both lubricated and oil-free one or several intercoolers. Since often 70-200°C. An aftercooler is used compressors need oil cooling. In compression generates heat, the to lower the temperature, which also oil-free compressors it is the lubrication compressed gas needs to be cooled results in condensation. The aftercooler oil for the gearbox that has to be between stages, making the is placed directly after the compressor cooled. In oil-injected compressors it is compression less adiabatic and more in order to precipitate the main part of the oil which is mixed with the isothermal. -
Prevent Engine Heater Hassles in Power Generators Reduce Low-Coolant Alarms, Low-Temperature Alarms and Service Calls
WHITE PAPER Automotive Off Road Heavy Power Duty Gen Prevent Engine Heater Hassles in Power Generators Reduce Low-Coolant Alarms, Low-Temperature Alarms and Service Calls A power generator’s engine heater is a critical component in providing fast, clean engine starts. Choosing and correctly installing a properly sized, high-quality heater protects the genset investment and ensures performance. Many diesel-power generator dealers, packagers, equipment rental companies and maintenance professionals are familiar with the frustration and cost of excessive low- coolant and low-temperature alarms resulting in service calls. Coolant evaporation can be caused by a thermosiphon circulation (TC) heater or incorrect installation of the heater. Dealers and packagers with service contracts are paying the price with replacement heaters and added service calls. Engine heater service issues are especially problematic for level-one care facilities, such as nursing homes and hospitals, where backup gensets must meet the NFPA 110, Type 10 regulation and start in less than 10 seconds. In Canada, CSA 282 requires engines to maintain a temperature between 100º and 120ºF (38º and 49ºC) to ensure quick startup. Mandatory for power generators, starting engines at these temperatures minimize wear and increase operating life. 1 WHITE PAPER Limited Engine Heater Choices To be cost-competitive, or due to lack of application information, gensets are often shipped with a low-cost engine heater. These heaters may not be suitable for all applications or meet the customer requirements. The dealer may need to upgrade the heater before the power generator is installed or in the field. To select the right engine pre-heater, it is important to be aware of new, more reliable products available today. -
Cooling Technology Institute
PAPER NO: 18-15 CATEGORY: HVAC APPLIcatIONS COOLING TECHNOLOGY INSTITUTE CLOSING THE LOOP – WHICH METHOD IS BEST FOR YOUR SYSTEM? FRANK MORRISON ANDREW RUSHWORTH BALTIMORE AIRCOIL COMPANY The studies and conclusions reported in this paper are the results of the author’s own work. CTI has not investigated, and CTI expressly disclaims any duty to investigate, any product, service process, procedure, design, or the like that may be described herein. The appearance of any technical data, editorial material, or advertisement in this publication does not constitute endorsement, warranty, or guarantee by CTI of any product, service process, procedure, design, or the like. CTI does not warranty that the information in this publication is free of errors, and CTI does not necessarily agree with any statement or opinion in this publication. The user assumes the entire risk of the use of any information in this publication. Copyright 2018. All rights reserved. Presented at the 2018 Cooling Technology Institute Annual Conference Houston, Texas - February 4-8, 2018 This page left intentionally blank. Page 2 of 32 Closing The Loop – Which Method is Best for Your System? Abstract Closed loop cooling systems deliver many benefits compared to traditional open loop systems, such as reduced system fouling, reduced risk of fluid contamination, lower maintenance, and increased system reliability and uptime. Several methods are used to close the cooling loop, including the use of an open circuit cooling tower coupled with a plate & frame heat exchanger or the use of a closed circuit cooling tower. This study compares the total installed cost of open circuit cooling tower / heat exchanger combinations versus closed circuit cooling towers, including equipment, material, and labor costs.