DOCSLIB.ORG

Thermal Design of Lithium Bromide-Water Solution

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thermal Design of Lithium Bromide-Water Solution THERMAL DESIGN OF LITHIUM BROMIDE-WATER SOLUTION VAPOR ABSORPTION COOLING SYSTEM FOR INDIRECT EVAPORATIVE COOLING FOR IT POD by DIGVIJAY RAMKRISHNA SAWANT Presented to the Faculty of the Graduate School of The University of Texas at Arlington in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE IN MECHANICAL ENGINEERING THE UNIVERSITY OF TEXAS AT ARLINGTON DECEMBER 2014 Copyright © by Digvijay R Sawant 2014 All Rights Reserved ii Acknowledgements I appreciate to my thesis advisor Dr. Dereje Agonafer, for his worthful guidance and corroborative support throughout my thesis. He has always helped me to make things happen which was slightly difficult for me in academics. I also want to thank my committee members, Dr. Kent Lawrence and Dr. Haji Sheikh for being in committee. I would like to thank each and every EMNSPC member at UTA for being with me and my research work. I thank Ms. Sally Thompson and Debi Barton for being such a excellent supportive staff. It gives me immense pleasure to thank my roommates and friends for being supportive to each other during happy and sad moments during our such great journey. Lastly but not least people who gave me a great support for everything I wanted to do, are my family members. I owe them a lot for being such supportive family. My brother Kamlesh and uncle Anil who is just not a brother and uncle but a best guide and friend. I owe them a lot in my life. Behind my most of the successes they always stood behind me. My mother always used to encourage me to do something new and my father was always behind me as a solid rock. My sister in law was always supported me for good thing. Thank you for being such a great, supportive and encouraging family. November 24, 2014 iii Abstract THERMAL DESIGN OF LITHIUM BROMIDE-WATER SOLUTION VAPOR ABSORPTION COOLING SYSTEM FOR INDIRECT EVAPORATIVE COOLING FOR IT POD Digvijay Sawant, MS The University of Texas at Arlington, 2014 Supervising Professor: Dereje Agonafer Nowadays with increase use of Internet, mobile there is increase in heat, which ultimately increases the efficient cooling system of server room or IT POD. Use of traditional ways of cooling system has ultimately increased CO₂ emission and depletion of CFC’s are serious environmental issues which led scientific people to improve cooling techniques and eliminate use of CFC’s. To reduce dependency on fossil fuels and environmental friendly system needed to be design. For being utilizing low grade energy source such as solar collector and reducing dependency on fossil fuel vapor absorption cooling system has shown a great driving force in today’s refrigeration systems. This LiBr-water absorption cooling consists of five heat exchanger namely: Evaporator, Absorber, Solution Heat Exchanger, Generator, and Condenser. The thermal design was done for a iv load of 23 kW and the procedure was described in the thesis. There are 120 servers in the IT POD emitting 196 W of heat each on full load and some of the heat was generated by the computer placed inside the IT POD. A detailed procedure has been discussed. A excel spreadsheet was to prepared with varying tube sizes to see the effect on flows and ultimately overall heat transfer coefficient. v Table of Contents Acknowledgements ................................................................................................ iii Abstract .................................................................................................................. iv List of Illustrations ............................................................................................... viii List of Tables ......................................................................................................... ix Chapter 1 Introduction to traditional data center and IT POD (Modular data center) .............................................................................................................. 1 1.1 Comparison of IT POD (Modular data center) and Traditional data center ........................................................................................................... 3 1.1 First Generation Modular data center ........................................................... 4 1.3 Second generation Modular data center ........................................................ 5 Chapter 2 Basic vapor compression refrigeration cycle ......................................... 6 2.1 Ammonia absorption refrigeration system ................................................... 9 2.2 Lithium bromide absorption refrigeration cycle ......................................... 10 2.3 Objective of the thesis ................................................................................. 11 Chapter 3 Equilibrium chart for aqueous bromide solutions ................................ 12 Chapter 4 Evaporator ............................................................................................ 13 4.1 Tube side heat transfer coefficient hi .......................................................... 13 4.1.1 Shah’s Method ..................................................................................... 14 vi 4.1.2 Kandalikar’s Method ........................................................................... 16 4.2 Shell Side heat transfer coefficient ho ........................................................ 16 Chapter 5 Absorber ............................................................................................... 18 5.1 Absorber Analysis ....................................................................................... 20 5.2 Shell Side Heat Transfer coefficient ho ...................................................... 20 5.3 Tube Side Heat Transfer coefficient hi ....................................................... 21 Chapter 6 Solution heat Exchanger ....................................................................... 22 6.1 Solution heat exchanger Analysis ............................................................... 22 6.2 Tubes side heat transfer coefficient hi ........................................................ 23 6.3 Shell Side heat transfer coefficient ho ........................................................ 24 Chapter 7 Generator .............................................................................................. 25 7.1 Analysis of Generator ................................................................................. 26 Chapter 8 Condenser ............................................................................................. 27 8.1 Condenser Analysis .................................................................................... 27 8.2 Tube side heat transfer coefficient hi .......................................................... 27 8.3 Shell side heat transfer coefficient ho ......................................................... 28 Chapter 9 Conclusion and future work ................................................................. 29 References ............................................................................................................. 32 Biographical Information ...................................................................................... 34 vii List of Illustrations Figure 1-1 First Containerized data center by Sun Microsystem .......................... 2 Figure 1-2 Modular vs Traditional Data Center deployment cost in US$ .............. 2 Figure 1-3 Comparison of Modular data center and Traditional data center .......... 3 Figure 1-4 Sun Microsystem Containerized data center ......................................... 5 Figure 2-1 Vapor compression refrigeration system .............................................. 6 Figure 2-2 Pressure enthalpy chart ......................................................................... 7 Figure 2-3 Lithium bromide refrigeration system ................................................ 10 Figure 3-1 Equilibrium chart for aqueous lithium bromide solution .................... 12 Figure 4-1 Evaporator analysis ..............................................................................13 Figure 5-1 Absorber analysis ................................................................................ 18 Figure 5-2 Effect of absorber inlet LiBr percentage ratio .................................... 19 Figure 5-3 Effect of solution strength ................................................................... 20 Figure 6-1 Solution heat exchanger analysis ........................................................ 22 Figure 7-1 Effect of generator temperature .......................................................... 25 Figure 7-2 Generator analysis ............................................................................... 25 Figure 8-1 Analysis of condenser ......................................................................... 27 viii List of Tables Table 9-1 State points of LiBr-Water absorption cooling system ........................ 29 Table 9-2 Values of Heat transfer coefficient(W/m^2 K) .................................... 30 ix Chapter 1 Introduction to traditional data center and IT POD (Modular data center) Data Center is “IT Equipment” which can execute functions like store, process, manage and interchange alphanumerical data and information either individually or simultaneously, in order to effect communication. Along with the fast progress in the economies, industries, technologies around the world, there is an epitomic development in the information management systems. In today’s world, basic activities
Load more

Recommended publications
  • Performance Comparison Between an Absorption-Compression Hybrid Refrigeration System and a Double-Effect Absorption Refrigeration Sys-Tem
    Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com Procedia Engineering 00 (2017) 000–000 ScienceDirect www.elsevier.com/locate/procedia Procedia Engineering 205 (2017) 241–247 10th International Symposium on Heating, Ventilation and Air Conditioning, ISHVAC2017, 19- 22 October 2017, Jinan, China Performance Comparison between an Absorption-compression Hybrid Refrigeration System and a Double-effect Absorption Refrigeration Sys-tem Jian Wang, Xianting Li, Baolong Wang, Wei Wu, Pengyuan Song, Wenxing Shi* Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Department of Building Science, Tsinghua University, Haidian District, Beijing 100084, China Abstract Conventional absorption refrigeration systems (ARSs), which are mainly driven by heat, have a competitive primary energy efficiency (PEE) compared with chillers driven by electricity. In the typical ARS, a large quantity of high-temperature heat is supplied into the generator, while a substantial amount of low-temperature heat is rejected to the environment from the condenser, it’s a huge waste. In order to decrease the input heat for generator and enhance the performance of conventional ARS, a kind of absorption-compression hybrid refrigeration system recovering condensation heat for generation (RCHG-ARS) was ever proposed. In the present study, the models of both RCHG-ARS and double-effect absorption refrigeration system (DEARS) are established, and the effects of different parameters on them are simulated and compared with each other. As a conclusion, the PEE of RCHG-ARS can be 29.0% higher than that of DEARS, and RCHG-ARS has a wider working conditions than DEARS due to the existence of the compressor.
    [Show full text]
  • Power Generation Technology by Hot Water Heating of Low Temperature Power Generations Using Ammonia and Ammonia-Water Mixture As Working Fluid
    Proceedings of the 6th Asian Geothermal Symposium, Oct. 26-29, 2004 Mutual Challenges in High- and Low- Temperature Geothermal Resource Fields, 5-7 POWER GENERATION TECHNOLOGY BY HOT WATER HEATING OF LOW TEMPERATURE POWER GENERATIONS USING AMMONIA AND AMMONIA-WATER MIXTURE AS WORKING FLUID Takumi HASHIZUME Waseda Univ., 17 Kikui-cho, Shinjuku-ku, Tokyo, 162-0044, Japan e-mail:[email protected] 1. INTRODUCTION The heat discharged without being used for surroundings including the factory waste heat is not a little. It is widely used when the temperature of the heat source is high, and it is used comparatively effectively. On the other hand, the heat is not effectively used for the heat source of a low temperature of 100℃ or less. As for the geothermal energy, this is similar. It is used as a geothermal power generation when the steam of the high temperature and high pressure is obtained, and the usage is not wide for the steam and the hot water of the low temperature and low pressure. If the use as heat in the hot spring, the indoor air-conditioning (heating), the greenhouse, and the road heating, etc. is excluded for the hot water of 100℃ or less, it is hardly used in Japan. In this paper, it introduces the power generation technology which obtains electricity from the hot water of 100℃ or less by using the power generation cycle when the medium with a low boiling point (low boiling point medium) is made an working fluid. 2. HEAT RECOVERY AND RANKINE CYCLE BY LOW BOILING POINT MEDIUM Rankine cycle consists of the pump, the evaporator, the turbine, and the condenser, and the working fluid circulates around each equipment in this order.
    [Show full text]
  • Investigating Absorption Refrigerator Fires (Part I)
    Orion P. Keifer Peter D. Layson Charles A. Wensley Investigating Absorption Refrigerator Fires (Part I) ATLANTIC BEACH, FLORIDA—In today’s recreational vehicles (RV), the then expels it when perco- most common refrigerator uses absorption refrigeration technology, lated in the boiler. It is this primarily because this type of system can operate on multiple sources action of the water which of power, including propane when electrical power is unavailable. makes the ammonia flow. These refrigerators have been under intense scrutiny in recent years The hydrogen in the re- due to numerous reported fires, apparently starting in the area of the frigeration coil maintains absorption refrigerator. Both the Dometic Corporation and Norcold a positive pressure of ap- Incorporated, two manufacturers of RV refrigerators, have been re- proximately 300-375 PSI quired by the National Highway and Traffic Safety Administration (2.07-2.59 MPa) when (NHTSA) to recall certain models of refrigerators which have been not in operation and, due identified as capable of failing in a fire mode. In summary, the three to its low partial pressure, NHTSA recalls indicate a fatigue crack may develop in the boiler tube promotes the evaporation of the cooling unit which may release sufficient pressurized flammable of the liquid ammonia. It coolant solution into an area where an ignition source is present. The should be noted that unlike NHTSA Recall Campaign ID Numbers are 06E076000 for Dometic conventional refrigeration (926,877 affected units), and 02E019000 (28,144 affected units) and systems which extensively 02E045000 (8,419 affected units) for Norcold. use copper due to its high thermal conductivity, the Applications Engineering Group, Inc.
    [Show full text]
  • Empirical Modelling of Einstein Absorption Refrigeration System
    Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 75, Issue 3 (2020) 54-62 Journal of Advanced Research in Fluid Mechanics and Thermal Sciences Journal homepage: www.akademiabaru.com/arfmts.html ISSN: 2289-7879 Empirical Modelling of Einstein Absorption Refrigeration Open Access System Keng Wai Chan1,*, Yi Leang Lim1 1 School of Mechanical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia ARTICLE INFO ABSTRACT Article history: A single pressure absorption refrigeration system was invented by Albert Einstein and Received 4 April 2020 Leo Szilard nearly ninety-year-old. The system is attractive as it has no mechanical Received in revised form 27 July 2020 moving parts and can be driven by heat alone. However, the related literature and Accepted 5 August 2020 work done on this refrigeration system is scarce. Previous researchers analysed the Available online 20 September 2020 refrigeration system theoretically, both the system pressure and component temperatures were fixed merely by assumption of ideal condition. These values somehow have never been verified by experimental result. In this paper, empirical models were proposed and developed to estimate the system pressure, the generator temperature and the partial pressure of butane in the evaporator. These values are important to predict the system operation and the evaporator temperature. The empirical models were verified by experimental results of five experimental settings where the power input to generator and bubble pump were varied. The error for the estimation of the system pressure, generator temperature and partial pressure of butane in evaporator are ranged 0.89-6.76%, 0.23-2.68% and 0.28-2.30%, respectively.
    [Show full text]
  • The Application of Solar Thermal Technologies for Air Conditioning in Building Energy Efficiency
    AR3A160 Lecture Series Research Methods The application of solar thermal technologies for air conditioning in building energy efficiency Name: Qian LAN Student number: 4185684 Date: 5th Jan 2013 Content 1. Introduction……………………………………………………………………………………………………… 3 2. The benefit……………………………………………………………………………………………………… 3 3. Use of solar thermal cooling / heat pump mode…………………………………………………4 3.1 Solar absorption air conditioning ……………………………………………………………… 4 3.2 Solar absorption refrigeration / Heat pump mode …………………………………… 4 3.3 Solar photovoltaic cells air conditioning cooling mode……………………………… 5 4. Summery………………………………………………………………………………………………………… 5 Notes ……………………………………………………………………………………………………………………… 6 Figure Index …………………………………………………………………………………………………………… 6 Reference ……………………………………………………………………………………………………………… 6 1. Introduction As we all know, solar energy is a type of clean energy, which was widely used throughout the world. Solar thermal technology also has already become one of the most popular strategies for sustainable architecture design at present. Since I will use this strategy in my design this time, I become interested in how the application of solar thermal technologies for air conditioning will contributes to the sustainable design in the aspects of benefits and typology. As a result, I choose this question as my research question, which can lead my design and teach me how to choose the specific technology in the design process with different context. 2. The benefit of “ Solar Energy Using for Air Conditioning” Why I want to choose the “Solar Energy Using for Air Conditioning” as my research question? As it known to all, one of the most important of sustainable architecture design is saving the energy consumption of the building. The energy consumption of the building meant the energy consumption during the process of heating, ventilation, air conditioning, lighting, household appliances, transportation, cooking, hot water supply and drainage and so on.
    [Show full text]
  • Physical Implementations of Quantum Absorption Refrigerators
    Physical implementations of quantum absorption refrigerators Mark T. Mitchison1, ∗ and Patrick P. Potts2, 3, y 1Institut f¨urTheoretische Physik, Albert-Einstein Allee 11, Universit¨atUlm, D-89069 Ulm, Germany 2Department of Applied Physics, University of Geneva, Chemin de Pinchat 22, 1211 Geneva, Switzerland. 3Physics Department and NanoLund, Lund University, Box 118, 22100 Lund, Sweden. (Dated: November 14, 2018) Absorption refrigerators are autonomous thermal machines that harness the spontaneous flow of heat from a hot bath into the environment in order to perform cooling. Here we discuss quantum realizations of absorption refrigerators in two different settings: namely, cavity and circuit quantum electrodynamics. We first provide a unified description of these machines in terms of the concept of virtual temperature. Next, we describe the two different physical setups in detail and compare their properties and performance. We conclude with an outlook on future work and open questions in this field of research. The investigation of quantum thermal machines is a subfield of quantum thermodynamics which is of particular practical relevance. A thermal machine is a device which utilizes a temperature bias to achieve some useful task (for recent reviews see e.g. [1{7] as well as Ref. [8], Part I). The nature of this task can vary, with the most prominent example being the production of work in heat engines. Further examples include the creation of entanglement [9], the estimation of temperature [10] and the measurement of time [11]. This chapter discusses physical implementations of quantum absorption refrigerators. There are two compelling reasons which motivate the pursuit of implementing exactly this thermal machine.
    [Show full text]
  • Study on a Novel Absorption Referigeration System at Low Cooling Temperatures Yijian He Yijian [email protected]
    Purdue University Purdue e-Pubs International Refrigeration and Air Conditioning School of Mechanical Engineering Conference 2012 Study on a Novel Absorption Referigeration System at Low Cooling Temperatures Yijian He [email protected] Zuwen Zhu Xu Gao Guangming Chen Follow this and additional works at: http://docs.lib.purdue.edu/iracc He, Yijian; Zhu, Zuwen; Gao, Xu; and Chen, Guangming, "Study on a Novel Absorption Referigeration System at Low Cooling Temperatures" (2012). International Refrigeration and Air Conditioning Conference. Paper 1267. http://docs.lib.purdue.edu/iracc/1267 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Complete proceedings may be acquired in print and on CD-ROM directly from the Ray W. Herrick Laboratories at https://engineering.purdue.edu/ Herrick/Events/orderlit.html 2335, Page 1 Study on a Novel Absorption Refrigeration System at Low Cooling Temperatures Yi Jian HE*, Zu Wen ZHU, Xu GAO, Guang Ming CHEN Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou, China (Phone/Fax:+86 571 87952464, [email protected]) * Corresponding Author ABSTRACT A novel absorption refrigeration system is proposed in this context using R134a+R23 mixed refrigerants and DMF solvent. The new system uses two-staged absorber in series to reduce the evaporation pressure and can obtain a lower refrigeration temperature by the low-grade thermal energy. From thermodynamic analysis, the key factors are discussed on the performances of the new system. Under the same working conditions, comparisons on the performances are also conducted between the new one and an auto-cascade absorption refrigeration system with single-absorber.
    [Show full text]
  • The Use of Geothermal Energy in Absorption Refrigeration Circuits
    TECHNICAL TRANSACTIONS CZASOPISMO TECHNICZNE ENVIRONMENT ENGINEERING ŚRODOWISKO 1-Ś/2015 RENATA SIKORSKA-BĄCZEK* THE USE OF GEOTHERMAL ENERGY IN ABSORPTION REFRIGERATION CIRCUITS ZASTOSOWANIE ENERGII GEOTERMALNEJ DO NAPĘDU ZIĘBIAREK ABSORPCYJNYCH Abstract The use of absorption refrigerators to produce cold can definitely reduce energy usage through the use of a heat from the geothermal resources. Absorption refrigerators do not have a negative impact on the natural environment. They are particularly economically attractive when there is a free energy source with a temperature of between 50 and 200°C. This article presents a hybrid absorption-compression refrigerator powered by geothermal energy used for the production of ice slurry for air-conditioning refrigeration. Keywords: hybrid absorption/compression refrigerator, water-ammonia absorption refri- gerator, geothermal energy Streszczenie Zastosowanie ziębiarek absorpcyjnych do produkcji zimna pozwala zdecydowanie ograni- czyć straty energii dzięki wykorzystaniu do ich napędu ciepła pochodzącego ze złóż geotermal- nych. Ziębiarki absorpcyjne nie mają negatywnego wpływu na środowisko naturalne. Są one szczególnie atrakcyjne ekonomicznie gdy istnieje darmowe źródło energii o temperaturze 50‒200°C. W artykule przedstawiono ziębiarkę hybrydową absorpcyjno-sprężarkową zasilaną energią geotermalną wykorzystywaną do produkcji lodu zawiesinowego do celów ziębienia w klimatyzacji. Słowa kluczowe: ziębiarka hybrydowa absorpcyjno/sprężarkowa, ziębiarka absorpcyjna wodno-amoniakalna, energia geotermalna DOI: 10.4467/2353737XCT.15.190.4395 * Ph.D. Eng. Renata Sikorska-Bączek, Institute of Thermal Engineering and Air Protection, Faculty of Environmental Engineering, Cracow University of Technology. 120 1. Introduction Due to the dwindling global resources of fossil fuels, and also because of the need to protect the environment from degradation, methods using alternative energy sources are becoming more and more popular.
    [Show full text]
  • Modelling and Data Validation for the Energy Analysis of Absorption Refrigeration Systems
    MODELLING AND DATA VALIDATION FOR THE ENERGY ANALYSIS OF ABSORPTION REFRIGERATION SYSTEMS David Estefano Martinez Maradiaga Dipòsit Legal: T.69-2014 ADVERTIMENT. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs. ADVERTENCIA. El acceso a los contenidos de esta tesis doctoral y su utilización debe respetar los derechos de la persona autora. Puede ser utilizada para consulta o estudio personal, así como en actividades o materiales de investigación y docencia en los términos establecidos en el art. 32 del Texto Refundido de la Ley de Propiedad Intelectual (RDL 1/1996). Para otros usos se requiere la autorización previa y expresa de la persona autora.
    [Show full text]
  • Thermodynamic Model of a Single Stage H2O-Libr Absorption Cooling
    E3S Web of Conferences 234, 00091 (2021) https://doi.org/10.1051/e3sconf/202123400091 ICIES 2020 Thermodynamic model of a single stage H2O-LiBr absorption cooling Siham Ghatos1,*, Mourad Taha Janan1, and Abdessamad Mehdari1 1Laboratory of Applied Mechanics and Technologies (LAMAT), ENSET, STIS Research Center; Mohammed V University in Rabat, Morocco. Abstract. Due to the dangerous ecological issues and the cost of the traditional energy, the use of sustainable power source increased, particularly solar energy. Solar refrigeration and air conditioner such as, absorption solar systems denote a very good option for cooling production. In present work, an absorption machine that restores the thermal energy produced by a flat plate solar collector in order to generate the cooling effect was studied. For the seek of good performances, it is necessary to master the modeling of the absorption group by establishing the first and second laws of the thermodynamic cycle in various specific points of the cycle. The main objective was to be able to finally size different components of the absorption machine and surge the coefficient of performance at available and high heat source temperature. A model were developed using a solver based on Matlab/Simulink program. The obtained results were compared to the literature and showed good performances of the adopted approach. 1 Introduction reinforcement techniques (cold or hot). The work of Gomri et al. [4] has shown that when the condenser- This nowadays, air conditioning is generally provided by absorber and the evaporator temperatures are changed classic mechanical compression machines that consume a from 33°C to 39°C, 4°C to 10°C, respectively, the COP considerable amount of electrical energy in addition to the values of the single, double and triple effect absorption toxic fluids used inside.
    [Show full text]
  • Performance of an Absorption Refrigerator Using a Solar Thermal Collector Abir Hmida, Nihel Chekir, Ammar Ben Brahim
    World Academy of Science, Engineering and Technology International Journal of Energy and Power Engineering Vol:12, No:10, 2018 Performance of an Absorption Refrigerator Using a Solar Thermal Collector Abir Hmida, Nihel Chekir, Ammar Ben Brahim 1 50% primary energy can be saved with 0.07 €/kW. Solar Abstract—In the present paper, we investigate the feasibility of a thermal cooling systems are energy saving systems; they thermal solar driven cold room in Gabes, southern region of Tunisia. convert directly thermal input into cooling output [9]-[11]. 3 The cold room of 109 m is refrigerated using an ammonia absorption Among available solar thermal cooling systems, solar machine. It is destined to preserve dates during the hot months of the absorption cooling system is competitive due to its relatively year. A detailed study of the cold room leads previously to the estimation of the cooling load of the proposed storage room in the high efficiency [9]. It is also environmentally safe since it operating conditions of the region. The next step consists of the works with natural refrigerants such water or ammonia [12]. estimation of the required heat in the generator of the absorption Solar thermal driven refrigeration systems usually consist of machine to ensure the desired cold temperature. A thermodynamic solar thermal collectors connected to thermal driven chillers analysis was accomplished and complete description of the system is [13]. determined. We propose, here, to provide the needed heat thermally A crucial application of the solar thermal refrigeration from the sun by using vacuum tube collectors. We found that at least 21m² of solar collectors are necessary to accomplish the work of the systems is food refrigeration.
    [Show full text]
  • Thermodynamics of Refrigeration
    REFRIGERATION Refrigeration ................................................................................................................................................. 2 What it is ................................................................................................................................................... 2 Ductless problem................................................................................................................................... 4 Humidity problem ................................................................................................................................. 5 Temperature-range problem .................................................................................................................. 6 Heat-flow-rate problem ......................................................................................................................... 6 Noise problem ....................................................................................................................................... 7 What it is not ............................................................................................................................................. 7 What it is for ............................................................................................................................................. 7 History ....................................................................................................................................................... 8 How
    [Show full text]