DOCSLIB.ORG

3 Aqueous Lithium Bromide Absorption Refrigeration System

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
3 Aqueous Lithium Bromide Absorption Refrigeration System DESIGN AND ANALYSIS OF TRI-GENERATION PLANT FOR HEATING, COOLING AND POWER A Thesis Presented By Dongchuan You to The Department of Mechanical and Industrial Engineering in partial fulfillment of the requirements for the degree of Master of Science in the field of Mechanical Engineering Northeastern University Boston, Massachusetts April 2021 i ACKNOWLEDGEMENTS It is my extreme pleasure to thank Professor Metghalchi for his guidance, patience, encouragement, and inspiration that he provided generously during my whole master studies, not only throughout the thesis but also in his class. It has been my honor to be his student and learning under his instruction. The author also would like to say thanks to his friends, Aobo Liu, Zhenyu Lu, Ziyu Wang and others who give me a helping hand on my way of studying abroad. It is really an unforgettable happy time to study, communicating with each other and I will never forget the encouragement when I am confusing and frustrating. Next, I must thank my parents sincerely, not only because of the financial support for my tuition and daily expenses, but also for their constant understanding, patience, encouragement during my whole master studies. I also want to thank the department, the college of engineering, for their assistance for my study for the past two years. I would like to say thank you to all professors who taught me with their kindness and try their best effort to guide me. Finally, please allow me to show my appreciation to all the people who have helped me in my master studies. It builds an impressive memory of my past time, an unforgettable journey on my learning road. ii ABSTRACT A new tri-generation plant for heating, cooling and power has been designed and analyzed. Tri-generation system has been studied in recent years and its advantages like energy saving and environmental safety has been proved. Research on improving their performance has been increasing lately. In this thesis, a new tri-generation plant, consisted of a supercritical carbon dioxide (sCO2) recompression Brayton cycle and aqueous lithium bromide absorption refrigeration cycle, has been designed and its performance has been determined. Mass, energy, entropy and exergy balances have been used to model sCO2 recompression Brayton cycle, aqueous lithium bromide absorption refrigeration cycle and the tri-generation power plant. Parametric studies have been done in all three cycles to investigate effects of operating conditions on the performance of the system. Results show efficiency of sCO2 recompression Brayton cycle increases when pressure ratio and maximum temperature increase; the coefficient of performance of the absorption refrigeration system increases when generator exit temperature increases; the exergetic efficiency of the tri-generation plant increase when pressure ratio increases. iii TABLE OF CONTENTS 1 Introduction……………………………………………………………………….…….1 2 Supercritical Carbon Dioxide Recompression Cycle……………………………………3 2.1 Background………………………………………………………………………...3 2.2 Description of Recompression Cycle………………………………………………4 2.3 Method and Assumptions……………………………………………………….….6 2.4 Thermodynamic Model…………………………………………………………….7 2.5 Results…………………………………………………………………………….10 2.5.1 Model 1………………………………………………………………….….10 2.5.1.1 Effects of Pressure Ratio……………………………………...….…10 2.5.1.2 Effects of Split Fraction…………………………………………….13 2.5.1.3 Effects of Maximum Temperature……………………………….....14 2.5.2 Model 2……………………………………………………...……………...16 2.5.3 Model Comparison…………………………………………………….…...19 2.6 Conclusion………………………………………………………………………..20 3 Aqueous Lithium Bromide Absorption Refrigeration System………………………....22 3.1 Background………………………………………………….……………………22 3.2 Refrigerators Description…………………………………………………………24 3.3 Mathematical Model………………...……………………………………………27 3.3.1 Working Fluid Property Calculation……………………………………….27 3.3.2 Analysis of Single-effect Cycle…………………………………………….28 3.3.3 Analysis of Double-effect Cycle…………………………………………...31 3.3.4 Assumptions and Parameters…………………………………………….…35 3.4 Results and Discussion……………………………………………………………36 3.4.1 Single-effect Cycle…………………………………………………...…….36 iv 3.4.1.1 Effect of Cooling Loads………………………………….……….…36 3.4.1.2 Effect of Evaporator Exit Temperature………………….….………37 3.4.1.3 Effect of Condenser Exit Temperature…………………..……….…38 3.4.1.4 Effect of Absorber Exit Temperature…………………….…………39 3.4.1.5 Effect of Generator Exit Temperature………………….…….……..39 3.4.1.6 Effect of Solution Energy Exchanger Effectiveness…….…….……41 3.4.2 Double-effect Cycle……………………………….………………….…….42 3.4.2.1 Effect of Cooling Loads……………………………………….……42 3.4.2.2 Effect of Evaporator Exit Temperature……………………….…….42 3.4.2.3 Effect of Upper Condenser Exit Temperature………………..…….43 3.4.2.4 Effect of Absorber Exit Temperature……………………….….…..43 3.4.2.5 Effect of Upper Generator Exit Temperature……………….….…..45 3.4.2.6 Effect of Solution Energy Exchanger Effectiveness……….….……46 3.4.2.7 Effect of Lower Condenser Exit Temperature……………….….….47 3.5 Conclusion………………………………………………………………………..48 4 Tri-Generation System Analysis……………………………………………………….50 4.1 Model description………………………………………………………………...50 4.2 Thermodynamic Model…………………………………………………………..52 4.3 Assumptions and Parameters…………………………………………………….54 4.4 Results……………………………………………………………………………55 5 Conclusion and Recommendation………………………………………………….…61 5.1 Conclusion……………………………………………………………………..…61 5.2 Recommendation…………………………………………………………………62 References……………………………………………………………..…………………63 Appendices..…...…………………………………………………………………..……..72 v Appendix Ⅰ MATLAB Code for sCO2 Recompression Cycle (Trial and Error)……..72 Appendix Ⅱ MATLAB Code for sCO2 Recompression Cycle (Newton-Raphson Iteration)………………………...………………………………………………….…75 Appendix Ⅲ MATLAB Code for Single-Effect Absorption Refrigeration System.....79 Appendix Ⅳ MATLAB Code for Double-Effect Absorption Refrigeration System…………...……………………………………………………………………81 Appendix Ⅴ MATLAB Code for Tri-Generation Plant………………………….…....83 1 CHAPTER 1 INTRODUCTION Tri-generation systems also known as combined cooling, heating and power (CCHP) systems, is becoming a major subject of research in order to improve energy efficiency of power generation, thermal energy needs of plants and refrigeration systems. Tri-generation systems include various new technologies, provide an alternative for the world to meet and solve energy-related problems such as energy shortages, energy supply security, emission control, conservation of energy, and energy economy [1]. Tri-generation systems mostly produce both electric and usable thermal energy on-site or near site and converts 75–80% of the fuel source into useful energy [2-3]. The research of tri-generation system has been heated up in recent years [4-8], covering analysis based on different energy source like solar power plant [9], geothermal energy [10-11], fuel cell [12-13]. Also, studies based on different types of cycles in the system, such as organic Rankine cycle [14], Kalina cycle [15], have been reported. The purpose of this thesis is to perform analysis of a given tri-generation consisted of supercritical carbon dioxide (sCO2) recompression cycle and aqueous lithium bromide refrigeration cycle. The effects of some operating variables, such us pressure ratio, generator exit temperature on energy effectiveness as well as exergetic efficiency have been evaluated. Chapter 2 covers complete design and analysis of a recompression super critical Brayton cycle based. Results of this chapter will be published in American Society of Mechanical Engineers (ASME) Journal of Energy Resources Technology (JERT). Chapter 3 is the design and analysis of both single effect as well as double effect water 2 lithium bromide absorption refrigerator system. A paper based on the results of chapter 3 will be published in JERT too. Chapter 4 is a complete Tri-generation system combing results of chapters 2 and 3 and also developing thermal energy for use as needed. Chapter 5 is the conclusion and recommendation of this study. 3 CHAPTER 2 SUPERCRITICAL CARBON DIOXIDE RECOMPRESSION CYCLE In this chapter, parametric analysis of different variables such as pressure ratio, split fraction and maximum temperature of the sCO2 recompression cycle have been performed. The effects of these variables on thermal efficiency as well as exergetic efficiency have been evaluated. 2.1 Background Carbon dioxide has been studied as a working fluid in power plants for years due to favorable high efficiency of the plant using carbon dioxide [16] and environmental safety [17]. Supercritical carbon dioxide can be used in different types of energy sources, such us nuclear [18], solar [19], coal fired [20,21] in topping cycles [22], bottom cycles [23] and power cycles [24]. Also, additional attributes of sCO2 Brayton cycle, such us impurities [25], pinch point analysis [26], convective energy transfer coefficient [27] have been reported. Ahn [28] wrote a review paper on the thermal efficiencies of sCO2 power conversion systems and applications with respect to the turbine inlet temperature. Geothermal, nuclear and solar power plants have excellent environmental attributes, but their most common efficiencies are less than 45% [29] because their turbine inlet temperature are mostly between 400-700 ℃, which are much lower than gas or steam turbine system. The sCO2 Brayton cycles, which have been studied in recent decades, can have higher thermal efficiency, about 5% higher while having lower turbine inlet temperature [28]. The main 4 advantage for the sCO2 Brayton cycle is that the
Load more

Recommended publications
  • An Analysis of the Brayton Cycle As a Cryogenic Refrigerator
    jbrary, E-01 Admin. BJdg. OCT 7 1968 NBS 366 An Analysis of the Brayton Cycle As a Cryogenic Refrigerator ITATIONAL BURSAL' OF iTANDABD8 LIBRABT MAR 6 J973 V* 0F c J* 0a <5 Q \ v S. DEPARTMENT OF COMMERCE in Q National Bureau of Standards %. *^CAU 0? * : NATIONAL BUREAU OF STANDARDS The National Bureau of Standards 1 was established by an act of Congress March 3, 1901. Today, in addition to serving as the Nation's central measurement laboratory, the Bureau is a principal focal point in the Federal Government for assuring maxi- mum application of the physical and engineering sciences to the advancement of tech- nology in industry and commerce. To this end the Bureau conducts research and provides central national services in three broad program areas and provides cen- tral national services in a fourth. These are: (1) basic measurements and standards, (2) materials measurements and standards, (3) technological measurements and standards, and (4) transfer of technology. The Bureau comprises the Institute for Basic Standards, the Institute for Materials Research, the Institute for Applied Technology, and the Center for Radiation Research. THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and consistent system of physical measurement, coor- dinates that system with the measurement systems of other nations, and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of an Office of Standard Reference Data and a group of divisions organized by the following areas of science and engineering Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic Phys- 2 2 ics—Cryogenics-—Radio Physics-—Radio Engineering —Astrophysics —Time and Frequency.
    [Show full text]
  • A Turbo-Brayton Cryocooler for Future European Observation Satellite Generation
    C19_078 1 A Turbo-Brayton Cryocooler for Future European Observation Satellite Generation J. Tanchon1, J. Lacapere1, A. Molyneaux2, M. Harris2, S. Hill2, S.M. Abu-Sharkh2, T. Tirolien3 1Absolut System SAS, Seyssinet-Pariset, France 2Ofttech, Gloucester, United Kingdom 3European Space Agency, Noordwijk, The Netherlands ABSTRACT Several types of active cryocoolers have been developed for space and military applications in the last ten years. Performances and reliability continuously increase to follow the requirements evolution of new generations of satellite: less power consumption, more cooling capacity, increased life duration. However, in addition to this increase of performances and reliability, the microvibrations re- quirement becomes critical. In fact, with the development of vibration-free technologies, classical Earth Observation cryocoolers (Stirling, Pulse Tube) will become the main source of microvibra- tions on-board the satellite. A new generation cryocooler is being developed at Absolut System using very high speed turbomachines in order to avoid any generated perturbations below 1000 Hz. This development is performed in the frame of ESA Technical Research Program - 4000113495/15/NL/KML. This paper presents the status of this development project based on Reverse Brayton cycle with very high speed turbomachines. INTRODUCTION The space cryogenics sector is characterized by a large number of applications (detection, im- aging, sample conservation, propulsion, telecommunications etc.) that lead to various requirements (temperature range, microvibration, lifetime, power consumption etc.) that can be met by different solutions (Stirling or JT coolers, mechanical or sorption compressors etc.). The recent years saw, in Europe, the developments of coolers to meet Earth Observation mission UHTXLUHPHQWVWKDWDUHFDSDEOHWRSURYLGHVLJQL¿FDQWFRROLQJSRZHUDWDQRSHUDWLRQDOWHPSHUDWXUH around 50K (for IR detection).
    [Show full text]
  • First and Second Law Evaluation of Combined Brayton-Organic Rankine Power Cycle
    Journal of Thermal Engineering, Vol. 6, No. 4, pp. 577-591, July, 2020 Yildiz Technical University Press, Istanbul, Turkey FIRST AND SECOND LAW EVALUATION OF COMBINED BRAYTON-ORGANIC RANKINE POWER CYCLE Önder Kaşka1, Onur Bor2, Nehir Tokgöz3* Muhammed Murat Aksoy4 ABSTRACT In the present work, we have conducted thermodynamic analysis of an organic Rankine cycle (ORC) using waste heat from intercooler and regenerator in Brayton cycle with intercooling, reheating, and regeneration (BCIRR). First of all, the first law analysis is used in this combined cycle. Several outputs are revealed in this study such as the cycle efficiencies in Brayton cycle which is dependent on turbine inlet temperature, intercooler pressure ratios, and pinch point temperature difference. For all cycles, produced net power is increased because of increasing turbine inlet temperature. Since heat input to the cycles takes place at high temperatures, the produced net power is increased because of increasing turbine inlet temperature for all cycles. The thermal efficiency of combined cycle is higher about 11.7% than thermal efficiency of Brayton cycle alone. Moreover, the net power produced by ORC has contributed nearly 28650 kW. The percentage losses of exergy for pump, turbine, condenser, preheater I, preheater II, and evaporator are 0.33%, 33%, 22%, 23%, 6%, and16% respectively. The differences of pinch point temperature on ORC net power and efficiencies of ORC are investigated. In addition, exergy efficiencies of components with respect to intercooling pressure ratio and evaporator effectiveness is presented. Exergy destructions are calculated for all the components in ORC. Keywords: Brayton Cycle, Organic Rankine Cycle, Bottoming Cycle, Pinch Point Temperature, Waste Heat, Energy and Exergy Analysis INTRODUCTION Thermal energy systems as well as corresponding all parts have been challenged to improve overall efficiency due to lack of conventional fuels, reduce climate change and so on for recent years.
    [Show full text]
  • Advanced Power Cycles with Mixtures As the Working Fluid
    Advanced Power Cycles with Mixtures as the Working Fluid Maria Jonsson Doctoral Thesis Department of Chemical Engineering and Technology, Energy Processes Royal Institute of Technology Stockholm, Sweden, 2003 Advanced Power Cycles with Mixtures as the Working Fluid Maria Jonsson Doctoral Thesis Department of Chemical Engineering and Technology, Energy Processes Royal Institute of Technology Stockholm, Sweden, 2003 TRITA-KET R173 ISSN 1104-3466 ISRN KTH/KET/R--173--SE ISBN 91-7283-443-9 Contact information: Royal Institute of Technology Department of Chemical Engineering and Technology, Division of Energy Processes SE-100 44 Stockholm Sweden Copyright © Maria Jonsson, 2003 All rights reserved Printed in Sweden Universitetsservice US AB Stockholm, 2003 Advanced Power Cycles with Mixtures as the Working Fluid Maria Jonsson Department of Chemical Engineering and Technology, Energy Processes Royal Institute of Technology, Stockholm, Sweden Abstract The world demand for electrical power increases continuously, requiring efficient and low-cost methods for power generation. This thesis investigates two advanced power cycles with mixtures as the working fluid: the Kalina cycle, alternatively called the ammonia-water cycle, and the evaporative gas turbine cycle. These cycles have the potential of improved performance regarding electrical efficiency, specific power output, specific investment cost and cost of electricity compared with the conventional technology, since the mixture working fluids enable efficient energy recovery. This thesis shows that the ammonia-water cycle has a better thermodynamic performance than the steam Rankine cycle as a bottoming process for natural gas- fired gas and gas-diesel engines, since the majority of the ammonia-water cycle configurations investigated generated more power than steam cycles.
    [Show full text]
  • Design of a Cryogenic Turbine for a Hybrid Cryocooler
    Design of a Cryogenic Turbine for a Hybrid Cryocooler by Thomas L. Fraser A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science (Mechanical Engineering) at the UNIVERISTY OF WISCONSIN-MADISON 2006 Approved by _____________________________________________ ______________ Professor Gregory F. Nellis Date i Abstract The hybrid pulse tube-reverse Brayton cycle cryocooler has the potential for cooling to temperatures on the order of 10 K. By using the rectifying interface which converts the oscillating pulse tube flow to continuous flow, both vibrations and low temperature regenerator losses are overcome, making the hybrid an ideal candidate for cooling infrared focal plane arrays which demand low temperature and low vibration. However, the turboexpander within the reverse Brayton cycle is complex and its performance is highly dependent on the performance of its subcomponents, thus necessitating a model predicting the turboexpander performance. A model was developed to predict the performance of the reverse Brayton cycle stage including the recuperative heat exchanger and turboexpander components. The turboexpander was numerically modeled in detail to include the sub-models of rotordynamics, the thermal and leakage performance of the seal, and the turboalternator. Where possible, the models were verified against either an analytical model or experimental data. A parametric analysis was carried out to determine the optimal design and conditions for the turboexpander. ii Acknowledgements First and foremost I would like to thank Greg Nellis. Besides being my advisor for this project he is also responsible for sparking an interest in energy science through his heat transfer courses I took as an undergrad.
    [Show full text]
  • Turbocharged Diesel Engine Power Production Enhancement: Proposing a Novel Thermal-Driven Supercharging System Based on Kalina Cycle
    Vol 1, No 2, 2020, 223-234 DOI: 10.22044/rera.2020.9521.1028 Turbocharged Diesel Engine Power Production Enhancement: Proposing a Novel Thermal-Driven Supercharging System based on Kalina Cycle 1 1 1 F. Salek , A. Eskandary Nasrabad and M.M. Naserian * 1- Department of Mechanical Engineering, Faculty of Montazeri, Khorasan Razavi Branch, Technical and Vocational University (TVU), Mashhad, Iran. Receive Date 3 April 2020; Revised 26 April 2020; Accepted Date 25 May 2020 *Corresponding authors: [email protected] (M. M. Naserian) Abstract In this paper, a novel thermal-driven supercharging system is proposed for downsizing of a turbocharged diesel engine. Furthermore, the Kalina cycle is used as a waste heat recovery system to run the mounted supercharging system. The waste heat of air in engine exhaust and intake pipes is converted to the cooling and mechanical power by the Kalina cycle. The mechanical power produced by the Kalina cycle is transferred to an air compressor to charge extra air to the engine in order to generate more power. This feature can be used for downsizing the turbo-charged heavy duty diesel engine. In addition, the heat rejected from the engine intercooler is transferred to the Kalina cycle vapor generator component, and part of the engine exhaust waste heat is also used for superheating the Kalina working fluid before entering the engine. Then the first and second law analyses are performed to assess the operation of the engine in different conditions. Moreover, an economic model is provided for the Kalina cycle, which is added to the engine as a supplementary component.
    [Show full text]
  • Thermodynamics of Power Generation
    THERMAL MACHINES AND HEAT ENGINES Thermal machines ......................................................................................................................................... 1 The heat engine ......................................................................................................................................... 2 What it is ............................................................................................................................................... 2 What it is for ......................................................................................................................................... 2 Thermal aspects of heat engines ........................................................................................................... 3 Carnot cycle .............................................................................................................................................. 3 Gas power cycles ...................................................................................................................................... 4 Otto cycle .............................................................................................................................................. 5 Diesel cycle ........................................................................................................................................... 8 Brayton cycle .....................................................................................................................................
    [Show full text]
  • Supercritical Carbon Dioxide(S-CO2) Power Cycle for Waste Heat Recovery: a Review from Thermodynamic Perspective
    processes Review Supercritical Carbon Dioxide(s-CO2) Power Cycle for Waste Heat Recovery: A Review from Thermodynamic Perspective Liuchen Liu, Qiguo Yang and Guomin Cui * School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; [email protected] (L.L.); [email protected] (Q.Y.) * Correspondence: [email protected] Received: 11 October 2020; Accepted: 13 November 2020; Published: 15 November 2020 Abstract: Supercritical CO2 power cycles have been deeply investigated in recent years. However, their potential in waste heat recovery is still largely unexplored. This paper presents a critical review of engineering background, technical challenges, and current advances of the s-CO2 cycle for waste heat recovery. Firstly, common barriers for the further promotion of waste heat recovery technology are discussed. Afterwards, the technical advantages of the s-CO2 cycle in solving the abovementioned problems are outlined by comparing several state-of-the-art thermodynamic cycles. On this basis, current research results in this field are reviewed for three main applications, namely the fuel cell, internal combustion engine, and gas turbine. For low temperature applications, the transcritical CO2 cycles can compete with other existing technologies, while supercritical CO2 cycles are more attractive for medium- and high temperature sources to replace steam Rankine cycles. Moreover, simple and regenerative configurations are more suitable for transcritical cycles, whereas various complex configurations have advantages for medium- and high temperature heat sources to form cogeneration system. Finally, from the viewpoints of in-depth research and engineering applications, several future development directions are put forward. This review hopes to promote the development of s-CO2 cycles for waste heat recovery.
    [Show full text]
  • Upgrading Both Geothermal and Solar Energy
    GRC Transactions, Vol. 40, 2016 Upgrading Both Geothermal and Solar Energy Kewen Li1,2, Changwei Liu2, Youguang Chen3, Guochen Liu2, Jinlong Chen2 1Stanford University, Stanford Geothermal Program, Stanford CA, USA 2China University of Geosciences, Beijing 3Tsinghua University, Beijing [email protected] Keywords Hybrid solar-geothermal systems, solar energy, geothermal resources, exergy, high efficiency ABSTRACT Geothermal energy has many advantages over solar and other renewables. These advantages include: 1) weather-proof; 2) base-load power; 3) high stability and reliability with a capacity factor over 90% in many cases; 4) less land usage and less ecological effect; 5) high thermal efficiency. The total installed capacity of geothermal electricity, however, is much smaller than those of solar energy. On the other hand, solar energy, including photovoltaic (PV) and concentrated solar power (CSP), has a lot of disadvantages and problems even it has a greater installed power and other benefits. Almost all of the five advantages geothermal has are the disadvantages of solar. Furthermore, solar PV has a high pollution issue during manufacturing. There have been many reports and papers on the combination of geothermal and solar energies in recent decades. This article is mainly a review of these literatures and publications. Worldwide, there are many areas where have both high heat flow flux and surface radiation, which makes it possible to integrate geothermal and solar energies. High temperature geothermal resource is the main target of the geothermal industry. The fact is that there are many geothermal resources with a low or moderate temperature of about 150oC. It is known that the efficiency of power generation from ther- mal energy is directly proportional to the resource temperature in general.
    [Show full text]
  • Thermodynamic Analysis of an Irreversible Maisotsenko Reciprocating Brayton Cycle
    entropy Article Thermodynamic Analysis of an Irreversible Maisotsenko Reciprocating Brayton Cycle Fuli Zhu 1,2,3, Lingen Chen 1,2,3,* and Wenhua Wang 1,2,3 1 Institute of Thermal Science and Power Engineering, Naval University of Engineering, Wuhan 430033, China; [email protected] (F.Z.); [email protected] (W.W.) 2 Military Key Laboratory for Naval Ship Power Engineering, Naval University of Engineering, Wuhan 430033, China 3 College of Power Engineering, Naval University of Engineering, Wuhan 430033, China * Correspondence: [email protected] or [email protected]; Tel.: +86-27-8361-5046; Fax: +86-27-8363-8709 Received: 20 January 2018; Accepted: 2 March 2018; Published: 5 March 2018 Abstract: An irreversible Maisotsenko reciprocating Brayton cycle (MRBC) model is established using the finite time thermodynamic (FTT) theory and taking the heat transfer loss (HTL), piston friction loss (PFL), and internal irreversible losses (IILs) into consideration in this paper. A calculation flowchart of the power output (P) and efficiency (η) of the cycle is provided, and the effects of the mass flow rate (MFR) of the injection of water to the cycle and some other design parameters on the performance of cycle are analyzed by detailed numerical examples. Furthermore, the superiority of irreversible MRBC is verified as the cycle and is compared with the traditional irreversible reciprocating Brayton cycle (RBC). The results can provide certain theoretical guiding significance for the optimal design of practical Maisotsenko reciprocating gas turbine plants. Keywords: finite-time thermodynamics; irreversible Maisotsenko reciprocating Brayton cycle; power output; efficiency 1. Introduction The revolutionary Maisotsenko cycle (M-cycle), utilizing the psychrometric renewable energy from the latent heat of water evaporating, was firstly provided by Maisotsenko in 1976.
    [Show full text]
  • Gas Power Cycles
    Week 11 Gas Power Cycles ME 300 Thermodynamics II 1 Today’s Outline • Gas turbine engines • Brayton cycle • Analysis • Example ME 300 Thermodynamics II 2 Gas Turbine Engine • Produces shaft power by GE H series power generation gas turbine. This 480-megawatt unit has a rated thermal expanding high enthalpy gas efficiency of 60% in combined cycle through a turbine configurations. • A compressor and a combustor produce the enthalpy increasing pressure and temperature, resp. • The spinning turbine rotates a shaft which drives the compressor • Remaining enthalpy can be used to drive a generator or can be expanded in a nozzle producing kinetic energy e.g. thrust ME 300 Thermodynamics II 3 Enthalpy Generation and Conversion Turbine Fuel converts enthalpy Generator to shaft power for Compressor Combustor electricity increases increases pressure Temperature Air (pv) (u) Nozzle converts enthalpy into kinetic energy ME 300 Thermodynamics II 4 Gas Turbine Engine Components http://www.stanford.edu/group/ctr/ResBriefs/temp05/schluter2.pdf www.aem.umn.edu/research/Images/pw_GasTurbine.gif ME 300 Thermodynamics II 5 Combustor Simulations ME 300 Thermodynamics II 6 Schematic • Fresh air enters compressors ~constant pressure • Air compressed to high pressure in compressor e.g. 23:1 • High pressure air is mixed with injected fuel spray in combustor raising temperatures • High enthalpy product gases expand in turbine producing shaft work to run compressor or Open cycle generator ME 300 Thermodynamics II 7 Air Standard Brayton Cycle • Model as closed cycle
    [Show full text]
  • Mathematical Analysis of Pulse Tube Cryocoolers Technology
    Global Journal of researches in engineering Electrical and electronics engineering Volume 12 Issue 6 Version 1.0 May 2012 Type: Double Blind Peer Reviewed International Research Journal Publisher: Global Journals Inc. (USA) Online ISSN: 2249-4596 & Print ISSN: 0975-5861 Mathematical Analysis of Pulse Tube Cryocoolers Technology By Shashank Kumar Kushwaha , Amit medhavi & Ravi Prakash Vishvakarma K.N.I.T Sultanpur Abstract - The cryocoolers are being developed for use in space and in terrestrial applications where combinations of long lifetime, high efficiency, compactness, low mass, low vibration, flexible interfacing, load variability, and reliability are essential. Pulse tube cryocoolers are now being used or considered for use in cooling infrared detectors for many space applications. In the development of these systems, as presented in this paper, first the system is analyzed theoretically. Based on the conservation of mass, the equation of motion, the conservation of energy, and the equation of state of a real gas a general model of the pulse tube refrigerator is made. The use of the harmonic approximation simplifies the differential equations of the model, as the time dependency can be solved explicitly and separately from the other dependencies. The model applies only to systems in the steady state. Time dependent effects, such as the cool down, are not described. From the relations the system performance is analyzed. And also we are describing pulse tube refrigeration mathematical models. There are three mathematical order models: first is analyzed enthalpy flow model and heat pumping flow model, second is analyzed adiabatic and isothermal model and third is flow chart of the computer program for numerical simulation.
    [Show full text]