Dynamic Modeling And Advanced Control Of Air Conditioning And Refrigeration Systems
DOWNLOAD
Download Dynamic Modeling And Advanced Control Of Air Conditioning And Refrigeration Systems PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Dynamic Modeling And Advanced Control Of Air Conditioning And Refrigeration Systems book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Dynamic Modeling And Advanced Control Of Air Conditioning And Refrigeration Systems
DOWNLOAD
Author : Bryan Philip Rasmussen
language : en
Publisher:
Release Date : 2005
Dynamic Modeling And Advanced Control Of Air Conditioning And Refrigeration Systems written by Bryan Philip Rasmussen and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2005 with categories.
Dynamic Modeling Simulation And Control Of Transportation Hvac Systems
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2013
Dynamic Modeling Simulation And Control Of Transportation Hvac Systems written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2013 with categories.
Modeling And Control In Air Conditioning Systems
DOWNLOAD
Author : Ye Yao
language : en
Publisher: Springer
Release Date : 2016-10-01
Modeling And Control In Air Conditioning Systems written by Ye Yao and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016-10-01 with Technology & Engineering categories.
This book investigates the latest modeling and control technologies in the context of air-conditioning systems. Firstly, it introduces the state-space method for developing dynamic models of all components in a central air-conditioning system. The models are primarily nonlinear and based on the fundamental principle of energy and mass conservation, and are transformed into state-space form through linearization. The book goes on to describe and discuss the state-space models with the help of graph theory and the structure-matrix theory. Subsequently, virtual sensor calibration and virtual sensing methods (which are very useful for real system control) are illustrated together with a case study. Model-based predictive control and state-space feedback control are applied to air-conditioning systems to yield better local control, while the air-side synergic control scheme and a global optimization strategy based on the decomposition-coordination method are developed so as to achieve energy conservation in the central air-conditioning system. Lastly, control strategies for VAV systems including total air volume control and trim & response static pressure control are investigated in practice.
Dynamic Modeling And Cascaded Control For A Multi Evaporator Supermarket Refrigeration System
DOWNLOAD
Author : Ankush Gupta
language : en
Publisher:
Release Date : 2013
Dynamic Modeling And Cascaded Control For A Multi Evaporator Supermarket Refrigeration System written by Ankush Gupta and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2013 with categories.
The survey from US Department of Energy showed that about one-third of energy consumption in US is due to air conditioning and refrigeration systems. This significant usage of electricity in the HVAC industry has prompted researchers to develop dynamic models for the HVAC components, which leads to implementation of better control and optimization techniques. In this research, efforts are made to model a multi-evaporator system. A novel dynamic modeling technique is proposed based on moving boundary method, which can be generalized for any number of evaporators in a vapor compression cycle. The models were validated experimentally on a commercial supermarket refrigeration unit. Simulation results showed that the models capture the major dynamics of the system in both the steady state and transient external disturbances. Furthermore the use of MEMS (microelectromechanical) based Silicon Expansion Valves (SEVs) have reportedly shown power savings as compared to the Thermal Expansion Valves (TEVs). Experimental tests were conducted on a supermarket refrigeration unit fitted with the MEMS valves to explain the cause of these potential energy savings. In this study an advanced cascaded control algorithm was also designed to control the MEMS valves. The performance of the cascaded control architecture was compared with the standard Thermal Expansion Valves (TEVs) and a commercially available Microstaq (MS) Superheat Controller (SHC). The results reveal that the significant efficiency gains derived on the SEVs are due to better superheat regulation, tighter superheat control and superior cooling effects in shorter time period which reduces the total run-time of the compressor. It was also observed that the duty cycle was least for the cascaded control algorithm. The reduction in duty cycle indicates early shut-off for the compressor resulting in maximum power savings for the cascaded control, followed by the Microstaq controller and then the Thermal Expansion Valves. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148111
Superheat Control For Air Conditioning And Refrigeration Systems Simulation And Experiments
DOWNLOAD
Author : Richard J. Otten
language : en
Publisher:
Release Date : 2010
Superheat Control For Air Conditioning And Refrigeration Systems Simulation And Experiments written by Richard J. Otten and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with categories.
Ever since the invention of air conditioning and refrigeration in the late nineteenth century, there has been tremendous interest in increasing system efficiency to reduce the impact these systems have on global energy consumption. Efficiency improvements have been accomplished through component design, refrigerant design, and most recently control system design. The emergence of the electronic expansion valve and variable speed drives has made immense impacts on the ability to regulate system parameters, resulting in important strides towards efficiency improvement. This research presents tools and methodologies for model development and controller design for air conditioning and refrigeration systems. In this thesis, control-oriented nonlinear dynamic models are developed and validated with test data collected from a fully instrumented experimental system. These models enable the design of advanced control configurations which supplement the performance of the commonly used proportional-integral-derivative (PID) controller. Evaporator superheat is a key parameter considered in this research since precise control optimizes evaporator efficiency while protecting the system from component damage. The controllers developed in this thesis ultimately provide better transient and steady state performance which increases system efficiency through low superheat set point design. The developed controllers also address the classical performance versus robustness tradeoff through design which preserves transients while prolonging the lifetime of the electronic expansion valve. Another notable contribution of this thesis is the development of hardware-in-the-loop load emulation which provides a method to test component and software control loop performance. This method alleviates the costs associated with the current method of testing using environmental test chambers.
The Control Handbook Three Volume Set
DOWNLOAD
Author : William S. Levine
language : en
Publisher: CRC Press
Release Date : 2018-10-08
The Control Handbook Three Volume Set written by William S. Levine and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-10-08 with Technology & Engineering categories.
At publication, The Control Handbook immediately became the definitive resource that engineers working with modern control systems required. Among its many accolades, that first edition was cited by the AAP as the Best Engineering Handbook of 1996. Now, 15 years later, William Levine has once again compiled the most comprehensive and authoritative resource on control engineering. He has fully reorganized the text to reflect the technical advances achieved since the last edition and has expanded its contents to include the multidisciplinary perspective that is making control engineering a critical component in so many fields. Now expanded from one to three volumes, The Control Handbook, Second Edition brilliantly organizes cutting-edge contributions from more than 200 leading experts representing every corner of the globe. They cover everything from basic closed-loop systems to multi-agent adaptive systems and from the control of electric motors to the control of complex networks. Progressively organized, the three volume set includes: Control System Fundamentals Control System Applications Control System Advanced Methods Any practicing engineer, student, or researcher working in fields as diverse as electronics, aeronautics, or biomedicine will find this handbook to be a time-saving resource filled with invaluable formulas, models, methods, and innovative thinking. In fact, any physicist, biologist, mathematician, or researcher in any number of fields developing or improving products and systems will find the answers and ideas they need. As with the first edition, the new edition not only stands as a record of accomplishment in control engineering but provides researchers with the means to make further advances.
Dynamic Modeling And Global Optimal Operation Of Multizone Variable Air Volume Hvac Systems Microform
DOWNLOAD
Author : Guo Rong Zheng
language : en
Publisher: National Library of Canada = Bibliothèque nationale du Canada
Release Date : 1997
Dynamic Modeling And Global Optimal Operation Of Multizone Variable Air Volume Hvac Systems Microform written by Guo Rong Zheng and has been published by National Library of Canada = Bibliothèque nationale du Canada this book supported file pdf, txt, epub, kindle and other format this book has been release on 1997 with Air conditioning categories.
Energy conservation and indoor environment concerns have motivated extensive research on various aspects of control of Heating, Ventilating and Air-Conditioning (HVAC) and building systems. The study on optimal operation as well as modeling of HVAC and building systems is one of the fastest growing fields that contribute to saving energy and improving indoor environment. This thesis is devoted to the development of a comprehensive modeling and optimization methodology for global multiple-stage optimal operation of HVAC and building systems. Two different dynamic models of a multizone variable air volume (VAV) system have been developed using (i) bottom-up and (ii) top-down approaches. The models take account of the dynamic interactions between building shell, VAV system components and control systems. The models describe the dynamics of fan, air distribution system, zone(s), cooling coil and primary plant (chiller) as one multivariable nonlinear system in a way that is useful for control analysis. Using the bottom-up approach a large-scale VAV system model has been developed. This model considers the interactions between flow field and thermal field via distributed capacity and variable air density considerations. An alternate model which is computationally more efficient was developed using the top-down approach. Model reduction techniques were applied to develop a reduced-order state space model of the VAV system. Results show that predictions from the reduced order model are within 5% of those from the large scale model. Optimal control schemes are developed for the efficient operation of VAV systems. In the control scheme proposed it is necessary to compute optimal setpoint profiles for local controllers. The optimal control profiles so computed can be used as tracking signals for local controllers for moving the system states from one setpoint to another. In order to determine optimal setpoint profiles an optimization methodology for formulating and solving the multiple stage optimal operation problems has been developed. The methodology is based on the maximum principle of Pontryagin and perturbation method in order to deal with the multiple time-scale of the HVAC processes and building operating schedules. A solution methodology and the corresponding computer models have been developed for solving the multiple stage optimal operation problems. The applications of the VAV model and the multistage optimization methodology have been demonstrated by considering several practical examples. The examples include (i) a comparison of optimal strategies for constant and variable air volume systems with and without time-of-day price structure for electrical energy, (ii) a two-zone VAV heating system and (iii) a five-zone VAV cooling system. Results showing the 24-hour optimal setpoint profiles, energy cost savings and the output responses such as zone temperatures and humidity ratios are given for different building operation schedules. These applications show that the developed models and optimization methodology can be used to determine energy efficient operating strategies for VAV systems without violating the thermal comfort in buildings.
Dynamic Modeling And Capacity Control Of Multiple Chiller Systems
DOWNLOAD
Author : Yang Guan
language : en
Publisher:
Release Date : 2005
Dynamic Modeling And Capacity Control Of Multiple Chiller Systems written by Yang Guan and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2005 with categories.
Dynamic Modeling And Multivariable Control Of Vapor Compression Cycles In Air Conditioning Systems
DOWNLOAD
Author : Xiang-Dong He
language : en
Publisher:
Release Date : 1996
Dynamic Modeling And Multivariable Control Of Vapor Compression Cycles In Air Conditioning Systems written by Xiang-Dong He and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1996 with categories.
Dynamic Modeling And Controls Of Variable Refrigerant Flow Systems
DOWNLOAD
Author : Liujia Dong
language : en
Publisher:
Release Date : 2019
Dynamic Modeling And Controls Of Variable Refrigerant Flow Systems written by Liujia Dong and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with Air source heat pump systems categories.
Building heating ventilation and air conditioning (HVAC) systems have significant impact on the energy consumption of residential and commercial buildings. The Variable Refrigerant Flow (VRF) systems, by distributing refrigerant instead of air flow, have emerged as an appealing class of HVAC system that features quieter operation, higher flexibility, and lower cost of installation and maintenance. However, such systems also present higher challenges for controls that can realize its achievable performance. This dissertation research proposes to investigate the dynamic simulation modeling and modelfree control strategies for energy efficient operation of VRF systems with single or multiple outdoor units (ODUs) under fluctuating and uncertain load and ambient conditions. Modelica based dynamic simulation models are developed for VRF systems of different configurations, which involve modeling of indoor units (IDUs), ODUs, and various control valves for thermal regulation. Motivated by a preliminary study on applying multi-variable extremum seeking control (ESC) for an air-source heat pump (ASHP) system, a model-free self-optimizing control strategy is investigated for efficient operation of a multi-functional VRF system under both heat pump modes and heat recovery modes. With the feedback of the total power only, the multi-variable ESC takes different combinations of manipulated inputs, including IDU superheat setpoints, compressor pressure setpoints, ODU fan speed, and ODU superheat setpoint. Input selection is carried out based on their respective impact on the total power. To realize automatic and smooth switching between different operation modes of multi-functional VRF system, the mode switching strategy is proposed. Whether to turn on or off an IDU is determined by the zone temperature and a preset hysteresis band about the temperature setpoint. Based on the thermodynamic analysis, a decision variable for determining the mode of ODU heat exchanger (HX) is proposed as the ODU-HX air-side temperature differential normalized by the dimensionless outdoor unit fan speed. For the smooth switching between two compressor pressure controllers, two bumpless transfer methods are applied. The simulation results validate the effectiveness of the proposed strategy and performance of bumpless transfer strategies. For the multi-ODU VRF systems, an integrated efficiency operation strategy is proposed to optimize the energy efficiency, which consists of three respects: i) for a given operating condition, a multi-variable ESC strategy is used to optimize the settings of manipulated inputs of operating ODUs, by use of a load-sharing valve array and feedback of the normalized total power; ii) a model-free ODU compressor staging strategy with ESC integrated control logic; and iii) a modelfree ODU heat exchanger mode switching strategy with ESC integrated control logic. For staging on additional ODU compressor, the saturated operation of compressor speed (i.e. saturated to the higher limit) is used as the indicating variable. With ESC-alike real-time optimization strategy in operation, the least efficient compressor would be driven, which will then be staged off. As for automatic mode switch of ODU heat exchangers during heat recovery operation, the saturation of IDU EEV opening is utilized as the indicating variable, and the ODU heat exchanger (or fan-coil unit) with least efficiency under ESC operation will switch its operational mode. Similar to many other HVAC systems, the ESC operation of VRF systems is subject to state and/or input constraints. In this dissertation research, the general problem of constrained ESC is studied. The penalty-functions based framework of constrained ESC is studied. The dither-demodulation design is modified for penalty-function based ESC with assumption of Wiener-Hammerstein system composition. An online penalty-weight adaptation scheme is proposed with online Hessian estimation, and its convergence analysis is conducted in the context of numerical optimization ESC (NOESC).