...COLD CHAIN PERFORMANCE ISSUES The cold chain remains one of the most important ways to preserve perishables and deliver them to market in good condition. The various requirements for success in the cold chain are identified, and examples of what can go wrong are given. Environmental issues are considered. Solutions for the future relating to produce, equipment, stowage and handling, and logistics are identified. The main requirements are for education and training and for provision of good operating systems. 1. INTRODUCTION The cold chain is generally considered as the transport and storage chain between the initial production and the final consumer of temperature-controlled perishable goods. This is not a complete definition, as there are other items carried under temperature control, for example works of art. For the purposes of this paper, only the transport and storage of perishable foodstuffs and pharmaceuticals will be considered. There are many types of cold chain. They may be categorised by carriage mode, by commodity, or by location and duration of transport. Air freight is generally limited to goods at chilled or ambient temperatures. Sea containers are universal in their application. Refrigerated ships carry bulk commodities in their holds, though increasingly these ships also carry containers. International land transport by road and/or rail is able to carry anything. Local distribution generally excludes the movement of bulk frozen goods. At...
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...Introduciton: In this experiment, three differnet thermodynamic cycle scenaro’s were given. Each was to be determined via tables and graphs: cold air-standard Brayton cycle, an ideal steam Rankine cycle, an an ideal vapor-compression refrigeration cycle. In each question, their would be a constant set to perform different calculations. This was done the desired amount. In the cold air-standard Brayton cycle, the thermal efficiency and net specific work output was needed with constant compressor pressure ratios of 6, 9, 12, and 15; while the turbine inlet temperatures were 800ºC, 1000ºC, 1200ºC, and 1400ºC. Then, the turbine inlet temperatures remained constant at 800ºC, 1000ºC, 1200ºC, and 1400ºC; while the compressor pressure ratios was 6, 9, 12, and 15. After all data was collected, four graphs were to be created by plotting the turbine inlet temperatures and the compressor pressure ratio versus the cycle thermal efficiency and net specific work output. For the ideal steam Rankine cycle, needed was to plot the cycle thermal efficiency by first setting the turbine exhaust pressures at a constant of 10, 50, and 100 kPa; and going through the turbine inlet pressures at 1, 5, and 8 MPa. Secondaly, it was needed to set the turbine exhaust pressures constant and going through a turbine inlet temperature of 300ºC, 500ºC, 700ºC. After all data was collected, two graphs were to be created. The first was plotted: the cycle thermal efficiency versus the turbine inlet temperatures...
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...APPLIED ENERGY www.elsevier.com/locate/apenergy Theoretical performances of various refrigerant–absorbent pairs in a vapor-absorption refrigeration cycle by the use of equations of state A. Yokozeki * DuPont Fluoroproducts Laboratory, Chestnut Run Plaza 711, Wilmington, DE 19880, USA Accepted 27 April 2004 Available online 28 July 2004 Abstract The vapor-absorption refrigeration cycle is an old and well-established technique, particularly with ammonia/water and water/LiBr systems. New types of refrigerant–absorbent pairs are also being actively studied. Modeling the cycle performance requires thermodynamic properties, which have been largely based on empirical correlation equations fitted to a large amount of experimental data such as solubility at various temperatures, pressures, and compositions. In this report, we have demonstrated, for the first time, a thermodynamically consistent model based on the equations of state for refrigerant–absorbent mixtures. Various commonly known binary-pairs for the absorption cycle are used as examples. Cycle performances and some new insights on understanding the cycle process are shown. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Vapor absorption cycle; Equations of state; Refrigerant; Absorbent; Modeling; Cycle performance; Solubility; Enthalpy 1. Introduction The vapor-absorption refrigeration cycle is more than 100 years old. Although the vapor-compression cycle took over most of air-conditioning and refrigerating * Tel...
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...Imagine this: it is a very hot day in July, you are watching T.V, your movements are as if you were a robot. Your fingers of your right hand are looking for a channel that gets your attention, and you found it. You have a comfortable posture in the couch, the windows open and fresh air coming through it. The T.V continues with the program until is commercial time. The commercial starts normal, then it shows a cool drink and suddenly you are thirsty. You get up and head to the refrigerator, you open it, and you got a really cold Coca-Cola. This past 200 years we have seen the big effect that ice had in our lives. It everything started as a theory, and idea, of Dr. Cullen, which the one consisted on the cooling effects of liquids evaporating in a vacuum. Then a lot more people started experimenting with this “cooling” theory. Even if he invented, he didn’t created, he just came up with the idea. Here I am going to tell you how this four scientists had revolutionized the refrigerator to how we use it today. But first let me tell you how the people did to storage their foods before the refrigerator. Do you remember the first example? Well you would said, that’s really easy, nothing to worry about. But imagine if you didn’t have the refrigerator. How would you have fresh food? How would you storage it? How would you be able to get a really cold cup of ice cream? Well we would suffer if the refrigerator wouldn’t exist. We are so dependent on the electricity and new technology that...
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...It is true that in a country which ranks first in milk production in the world, is number 2 in fruits & vegetables production and has substantial production of marine, meat & poultry products, the country needed a fully developed cold chain sector. However the current scenario reveals that there is a tremendous scope for the development of cold chain facilities. The cold storage sector is undergoing a major metamorphosis, with the Government focusing on food preservation. A lot of stress is being laid on energy efficiency as the cold stores are energy intensive. With the advent of newer materials / equipments, every part of a cold chain renders itself amenable for improvement. As a result type of construction, insulation, refrigeration equipment, type of controls – all of them are witnessing changes. Realizing the significance of the cold chain industry, it is heartening to note that the Govt has taken initiatives, thru bodies like NHB, to establish standards for all the arms of the cold chain. Efforts are also being made to evolve a new concept – ‘Green Cold Chain’. In short the Cold Chain Industry is in the eye of a revolution. The paper would cover the development of cold storage sector in India with progressive changes in pattern of...
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...mouth. Then you wonder how easy it is to have all your favorite food in front you. The concept of refrigeration is not a new one. Refrigeration by means of natural ice has been employed for thousands of years. Ice cellars were used in China as early as 1000 b. c. (Grolier 331-334). In warm seasons the ice was shipped to markets in the south. Not only did people quarry the ice, but they also had to deliver it homes to put inside an ice box, thus resulting in the neighborhood iceman who brought the ice. A refrigerator is an essential item in almost every household today. As more are marketed, there is a demand for better quality, better efficiency, and more modern refrigeration. They are used not only to store leftovers, but also pre-cooked meals as well. Human culture has evolved greatly around refrigerators. Stress can develop in a house hold when there is a family to feed, however with refrigeration only a simple planning is needed. By purchasing ready to eat food a parent can simply heat or serve ready to eat meals. This trend towards buying the necessary began, in part, with the introduction of the refrigerator, and many other household "time savers"; as less time was spent on family necessities, like meal purchase and preparation, and more time and money could be spent on items once thought frivolous Also, where once only individual ingredients were available, with refrigeration, meals or the meal components...
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...Journal of Mechanical Engineering and Automation 2015, 5(1): 20-28 DOI: 10.5923/j.jmea.20150501.03 Effect of Evaporator Heater Power Input and Refrigerant Flow Rate on the Performance of a Refrigerator – Developing Empirical Models Ali Naif*, Abdulkareem Shafiq Mahdi Al-Obaidi, Mohammad H. Nassir School of Engineering, Taylor’s University, Malaysia Abstract Refrigerators normally are systems that are used to preserve perishable goods in a house hold by reducing the temperature of the food compartments. However, refrigerators are also infamous for their high electricity consumptions. This paper presents first a comparison between theoretical and experimental determination of the tons of refrigeration (TR) of a vapor compression refrigeration cycle (VCRC). Then, it was looked into the derivation of empirical models, grounded on experimental results, which would provide refrigerator designers a reliable mean to check on the impact of each examined parameter on the TR during the preliminary stage of refrigerator design. It was noted that both evaporator heater power input (EHPI) and refrigerant flow rate (RFR) positively affected the tons of refrigeration, while the effects of condenser water flow rate (CWFR) was negligible. A total of three models generated. As the accuracy of the data for all models were about 99.7%, the minute difference had to be looked in to. Hence, Model 1, considering both evaporator heater power input (EHPI) and refrigerant flow rate (RFR)...
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...| | Téléchargez l'applicationJoin us on Facebook * Press room * Contact * Press releases * Media partners * Events at Rungis * Photo library * Video library * Education * Rungis education programme * School discovery visits * Jobs * Survey * Market jobs * Conferences (les entretiens) * Rungis leads the debate * Les Entretiens de Rungis this year * Previous editions * Products and features * Seasonal produce * Features * New products Newsletter | * Market areas * Buy * Setting at Rungis * Local produce * Supply * Current market prices * Who does what at Rungis * Introduction * Rungis Values * Health and Safety * Sustainable development * International * Semmaris * Press room * Education * Jobs * Conferences (les entretiens) * Products and features * Trading times and closing dates * Traffic information * How to get to Rungis * Market Map * Eating * Sleeping * Your communication at Rungis * Setting-up at Rungis * Book a reception room * Visit Rungis * Photo library * Video library * Who does what at Rungis * Why setting-up at Rungis * Property * Request information * They set-up at Rungis Home » Media/Education/Jobs » Products and features >> FeaturesFeatures The cold chain : facilities and regulationsThe cold chain occupies an essential place in the food...
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...Refrigeration Cycles Content: The ideal vapor-compression refrigeration cycle vaporActual Vapor-Compression Refrigeration Cycle VaporHeat Pump System for Heating and Cooling Innovative Vapor-Compression Refrigeration Cycle VaporGas Refrigeration Cycles Absorption Refrigeration Systems Refrigerants Selection Refrigeration affects many areas of your life The obvious: Refrigerator/Freezers allow food preservation Air conditioning Refrigerated fishing boats allow preservation of catch Refrigerated trucks are used to ship fruits/meats Refrigeration makes possible medical procedures that call for lowering body temperatures Refrigerator and Heat Pump The objective of a refrigerator is to remove heat (QL) from the cold medium; the objective of a heat pump is to supply heat (QH) to a warm medium. Schematic diagram of the ideal vaporcompression refrigeration cycle Compressor Condenser Evaporator Simple view of household refrigerator T-s Diagram of the Ideal Refrigeration Cycle Process 1-2 Isentropic Compression Process Process 2-3 P = const. Heat Rejection Process const. Process 3-4 Expansion under Throttling Process, h = const Process 4-1 P = const. Heat Addition Process const. P-h Diagram of the Ideal Refrigeration Cycle Process 1-2 Isentropic Compression Process Process 2-3 P = const. Heat Rejection Process const. Process 3-4 Expansion under Throttling Process, h = const Process 4-1 P = const. Heat Addition Process const. Coefficient of Performance...
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...Introduction Magnetic refrigeration has become an emerging technology that has the potential for high energy efficiency. It makes use of the magnetocaloric effect found in solid state refrigerants. Sold state refrigerants are instruments used either for heating or cooling, although the main application here is cooling. The combination of solid state rrefrigerants, water based heat transfer fluids and high efficiency fluids leads to environmental freindly products, which minimizes contribution to current global warming issue. The magnetocaloric effect was originally found in the 18th century, by E. Warburg (1881) in pure iron, where the cooling effect only varied between 0.5 to 2 K/T. Then in the late 1920s, major advances appeared when two scientists: Debye (1926) and Giauque (1927) proposed cooling via adiabatic demagnetization. A few years later in 1933, Giauque and MacDougall demonstrated the process for cryogenic purposes and managed to achieve a temperature of 0.25K (Cryogenic meaning the study of the production of very low temperatures and behavior of materials at those temperatures). Advances occurred through the years up to 1997, until the first near room temperature proof of magnetic refrigerator concept was demonstrated by Professor Karl A. Gschneidner, Jr. from Iowa State University. This discovery drew attention and interests from scientists and companies worldwide. Since then new kinds of room temperature materials and magnetic refrigerator designs have developed...
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...Nomination Scheme visa, a Subclass 457 (Business (Long Stay)) visa or a Subclass 442 (Occupational Trainee) visa you must nominate an occupation from either Schedule 1- Skilled Occupation List or Schedule 2 Consolidated Sponsored Occupation List. Applicants who require a skills assessment as part of their visa application must contact a relevant assessing authority directly to obtain a skills assessment. The assessing authority will provide all necessary applications forms and associated information relating to the assessment. There will be a charge by the assessing authorities for the assessment. See: http://www.immi.gov.au/skilled/_pdf/assessing-authorities.pdf (134KB PDF file) OCCUPATION Construction Project Manager Project Builder Engineering Manager Production Manager (Mining) Child Care Centre Manager Medical Administrator Nursing Clinical Director Primary Health Organisation Manager Welfare Centre Manager Accountant (General) Management Accountant Taxation Accountant External Auditor Internal Auditor Actuary Land Economist Valuer Ship's Engineer Ship's Master Ship's Officer Architect Landscape Architect Cartographer Other Spatial Scientist ANZSCO CODE 133111 133112 133211 133513 134111 134211 134212 134213 134214 221111 221112 221113 221213 221214 224111 224511 224512 231212 231213 231214 232111 232112 232213 232214 ASSESSING AUTHORITY VETASSESS VETASSESS Engineers Australia/AIM VETASSESS...
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... | |Thursday |EN010 102 |Common for all branches | | | |07.05.2015 |Engineering Physics | | | | |Monday |EN010 103 Engineering Chemistry & |Common for all branches | | | |11.05.2015 |Environmental | | | | | |Studies | | | | |Wednesday |EN010 101 |Common for all branches | | | |13.05.2015 |Engineering Mathematics-I | | | | |Friday |EN010 106 Basic Civil Engineering |Common for all branches | | | |15.05.2015 | | | | | |Tuesday |EN010 107 Basic Mechanical Engineering |Common for all branches | | | |19.05.2015 |...
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...Course code: 15MA101 | Engineering Mathematics | L | T | P | C | | | 3 | 1 | - | 4 | Course Objectives | To train the students in basic mathematics essential for modeling and solving engineering problems. | Course Outcomes | 1. An ability to apply knowledge of mathematics, science and engineering. 2. An ability to identify, formulate and solve engineering problems | Differential Calculus: Review: Functions and graphs, Limits and Continuity, Differentiation, Maxima and minima of a function, Rolle’s Theorem, Mean Value Theorem. Indeterminate forms and L'Hopital's rule, Infinite sequences and series, Power series, Taylor's and Maclaurin's series, Convergence of Taylor's series, Error Estimates, Polar coordinates and Polar equations. Functions of two or more real variables, Partial derivatives of second and higher order, Euler’s theorem on homogenous function, Total derivatives, Differentiation of composite and implicit functions, Change of variable, Jacobians, Maxima and minima of functions of two or more variable, Lagrange’s method of undetermined multipliers. Integral Calculus: Estimating with finite sums and limits of finite sums, Definite integral, The fundamental theorem of calculus, Trigonometric substitutions, Integration by reduction formula for powers of some trigonometric functions, Improper integrals, Beta and Gamma integrals. Double integrals, Triple...
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...Question With the aid of a suitable diagram, describe the operation and construction of a reciprocating compressor employed in a VCR system (30 marks). Introduction A compressor is the most important and often the costliest component of any vapour compression refrigeration system (VCRS). The function of a compressor in a VCRS is to continuously draw the refrigerant vapour from the evaporator, so that a low pressure and low temperature can be maintained in the evaporator at which the refrigerant can boil extracting heat from the refrigerated space. The compressor then has to raise the pressure of the refrigerant to a level at which it can condense by rejecting heat to the cooling medium in the condenser. Reciprocating compressors Description Reciprocating compressor is the workhorse of the refrigeration and air conditioning industry. It is the most widely used compressor with cooling capacities ranging from a few Watts to hundreds of kilowatts. Modern day reciprocating compressors are high speed (≈ 3000 to 3600 rpm), single acting, single or multi-cylinder (up to 16 cylinders) type. Construction features and Principle of Operation Fig. 1 Figure 1 shows the schematic of a reciprocating compressor. Reciprocating compressors consist of a piston moving back and forth in a cylinder, with suction (Sv) and discharge (Dv) valves to achieve suction and compression of the refrigerant vapour. Its construction and working are somewhat similar to a two-stroke engine, as...
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...Curriculum Vitae Rameshkumar N. Tank B.Tech (Mechanical) C-38, Arti Society, Nr.Shalin School, Payal Nagar Road, Naroda, Ahmedabad -30. Mobile No.: 9904156898 Email: mech_rameshtank@yahoo.com Career Objective: To achieve key Middle Management position in Production/Maintenance, Purchase, Materials Management, field by being an integral part of continuous emerging, learning & to the core employee & value centric organization thus enables me to utilize my experience, skills & knowledge in the growth of organization. Professional Experience: • Currently working with Henley Industries (India) Ltd., Ahmedabad, as a Production & Purchase Executive Since 1st June 2010. Company Profile: • HENLEY INDUSTIRES (INDIA) LIMITED Ahmedabad is a Multinational Company and Henley Group having three main companies i.e. Drury Industries Ltd, Chemiron International Ltd, and Henley Industries Ltd. with a diversified interest in the field of Chemicals and Medicine formulations. Henley Group of Companies is 500-crore company, based in UK with its main line of products include Sulfuric Acid, Aluminum Sulfate, Silicate and Pharmaceutical Products. With its various plants located in Nigeria – West Africa with dedicated workforce of 3000 employees. Work Profile: • Production: Monitoring the daily production at the plant and keeping all the records of daily production as well as the problems regarding the production, Troubleshooting and fixing the problems. Prepare...
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