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Analysis and Experimental Investigation on HVAC System Energy conservations of a Library BuildingWu, Yan-jia 31 May 2005 (has links)
The electrical power has been applied in many applications extensively since the industrial revolution and becomes the main energy source in the 21th century. Because of the fast economic growth, the electrical power demands have increased extensively in the past 30 years. In recent years, number of semiconductor factories have been built in Taiwan and bring the electrical power not enough in the summer. Because the climate is hot and humid in Taiwan, energy consumption of air conditioning is half of total consumption of the building, and the energy consumption of chiller plant is more than 30% of total consumption of HVAC system.
Based on field measurement data, the air-conditioning system consumes more than 40% of the building total energy use, followed by 30% of lighting, and 30% of miscellaneous pumping systems.. Among them, 60% power was consumed by chiller plants, while the chilled water pumping and air side equipment each accounts for another 20%. It is no doubt, that the energy efficiency improvement of chillers is one of the most important items in building energy conservation.
The capacity of HVAC system in many Taiwan¡¦s big buildings has the situation that the designed capacity is much larger than the actual required, and this Oversize Design of HVAC system caused waste of extra equipment and cost. In this content, we offer improvement methods that are predicated on the HVAC system waste situation, and provide the prediction of efficient. As most of HVAC system in existing building have Oversize Design problem, it caused HVAC engines are with low efficiency and loading, and energy wasting is getting worse and worse. Besides, some existing engines may keep running over 10 years; the performance is far behind the new type engine. According to the existingsystem¡¦s running status, we can have the precise HVAC¡¦s loading, and redesign the conformable HVAC¡¦s engine type to make it is under efficient operation; furthermore, in order to be energy-saving, we design the best proper sets based on loading capacity, and change to new type HVAC engine with high performance, also, we improve the design of water system.
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BEMS-assisted Commissioning of HVAC System Energy Conservation DesignsChen, Lin-Hung 20 July 2008 (has links)
In recent years, Green Building Promotion program has made a significant progress where 1359 cases have acquired the Green Building Candidate Certificate. Among them, 245 cases or 18% in total, eventually received the Green Building Label which is considered low and need to be improved.
On the other hand, in United States where LEED is applied, the Commissioning, abbreviated as Commissioning, has been deemed as a Pre-Requisite Requirement for all LEED Projects. In ASHRAE design guides, Commissioning has been defined as a procedure through testing, adjusting, and balancing, to Perform in Conformity with the Design Intent.
The goals of Owners, designers, and engineering contractors can all be integrated and optimized where design intent can be fulfilled with traceable records during the Commissioning process.
Though Testing, Adjusting, Balancing, and Commissioning, building energy efficiency can be upgraded where energy savings and CO2 emission reduction can be obtained.
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Energy Consumption Modeling in Wireless Sensor Networked Smart HomesXie, Wang January 2015 (has links)
Smart home automation is the dwelling bridge of smart grid technology, as it
integrates the modern home appliances power consumption information over
communication networks in the smart grid system. Among all the appliances,
Heating, Ventilation and Cooling (HVAC) systems is one of the most primary
concerns. Since a great amount of power consumption is contributed by these HVAC
systems. Traditionally, HVAC systems run at a fixed schedule without automatic
monitoring and control systems, which causes load variation, fluctuations in the
electricity demand and inefficient utility operation. In this thesis, we propose a Finite
State Machine (FSM) system to model the air condition working status to acquire the
relationship between temperature changing and cooling/heating duration. Finally, we
introduce the Zigbee communciation protocol into the model, the performance
analysis of the impact of end-to-end delay over HVAC systems is presented.
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Investigation of the energy efficient sustainable manufacturing approach and its implementation perspectivesKatchasuwanmanee, Kanet January 2016 (has links)
In the last two decades, energy is becoming one of the main issues in the manufacturing industry as it contributes substantially to production cost, CO2 emissions, and other destructive environmental impact. Due to rising energy costs, environmental concerns and stringent regulations, manufacturing is increasingly driven towards sustainable manufacturing which needs to address the associated environmental, social and economic aspects simultaneously. One common approach is to achieve sustainability and to implement energy-resource efficient production management systems that enable optimisation of energy consumption and resource utilisation in the production system. However, by reducing energy consumption, the product quality and production cost may be compromised. To remain competitive in the dynamic environment, the energy-efficient management system should not only concern energy consumption but also maintain product quality and production efficiency. This thesis presents a development of the Energy-smart Production Management (e-ProMan) system which provides a systematic, virtual simulation that integrates manufacturing data relating to thermal effect and correlation analysis between energy flow, work flow and data flow for the heating, ventilation and air conditioning (HVAC) system and production process. First, the e-ProMan system comprises of the multidimensional analysis between energy flow, work flow and data flow. The results showed that the product quality is significantly affected by ambient temperature in CNC precision machining. Product quality appears to be improved at lower temperatures. This research highlights the significance of ambient temperature in sustainable precision machining. Second, the simulation experiment was modelled at the production process due to it being the main source of energy consumption in manufacturing. An up-hill workload scenario was found to be the most energy and cost-efficient production processes. In other words, energy consumption, CO2 emission and total manufacturing cost could be reduced when workload capacity and operating machine increase incrementally. Moreover, the e-ProMan system was modelled and simulated using the weather forecast and real-time ambient temperature to reduce energy consumption of the HVAC system. The e-ProMan system results in less energy consumption compared to the fuzzy control system. To conclude, the e-ProMan demonstrates energy efficiency at all relevant levels in the manufacturing: machine, process and plant. For the future research, the e-ProMan system needs to be applied and validated in actual manufacturing environments.
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Development of BEMS Diagnostic and Intelligent Expert Technology for Air-conditioning SystemsDai, Chi-fu 11 June 2012 (has links)
When central HVAC systems are under commercial operation, all operational parameters, including chilled water supply temperature, return water temperature, chilled water flow rate, and power consumption as the key factors in affecting system energy efficiency.However, in Taiwan there is still lacking of the regression equations of chillers under local weather conditions, and has to rely on manual operation based on experiences. This is also the major short-comings in implementing TAB, and is the best way to renovate the green buildings to make them more intelligent.
In this study, theoretical analysis and experimental investigation will be applied simultaneously. In selecting cases from the BeeUp program, actual operational data including COP can be fitted into experimental model to facilitate TAB engineering via BEMS system, in achieving system efficiency.
Through the execution of this project, it is identified that the exhibition buildings with 10 hours cooling load, can achieve 7% energy savings. The good result obtained in this project , including the thermal energy storage HVAC system and the heat pump system can be widely adapted to obtain significant energy conservation effect.
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Improvements and Applications of the Methodology for Potential Energy Savings Estimation from Retro-commissioning/Retrofit MeasuresLiu, Jingjing 16 December 2013 (has links)
This thesis has improved Baltazar's methodology for potential energy savings
estimation from retro-commissioning/retrofits measures. Important improvements and
discussions are made on optimization parameters, limits on optimization parameter
values, minimum airflow setting for VAV systems, space load calculation, simulation of
buildings with more than one type of system, AHU shutdown simulation, and air-side
simulation models. A prototype computer tool called the Potential Energy Savings
Estimation (PESE) Toolkit is developed to implement the improved methodology and
used for testing.
The implemented methodology is tested in two retro-commissioned on-campus
buildings with hourly measured consumption data. In the Sanders Corps of Cadets
Center, the optimized profiles of parameter settings in single parameter optimizations
can be explained with engineering principles. It reveals that the improved methodology
is implemented correctly in the tool. The case study on the Coke Building shows that the
improved methodology can be used in buildings with more than one system type.
The methodology is then used to estimate annual potential energy cost savings
for 14 office buildings in Austin, TX with very limited information and utility bills. The
methodology has predicted an average total potential savings of 36% for SDVAV
systems with electric terminal reheat, 22% for SDVAV systems with hot water reheat,
and 25% for DDVAV systems. The estimations are compared with savings predicted in
the Continuous Commissioning assessment report. The results show it may be helpful
to study the correlation by using generalized factors of assessment predicted energy cost
savings to estimated potential energy cost savings. The factors identified in this
application are 0.68, 0.66, and 0.61 for each type of system. It is noted that one should
be cautious in quoting these factors in future projects.
In the future, it would be valuable to study the correlation between measured
savings and estimated potential savings in a large number of buildings with retrocommissioning
measures implemented. Additionally, further testing and modifications
on the PESE Toolkit are necessary to make it a reliable software tool.
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Automação de um sistema de climatização para abrigos de equipamentos eletrônicosFabio Marquini Facchini 26 June 2012 (has links)
O objetivo deste trabalho foi desenvolver um sistema para atender as necessidades de controle e automação de um sistema de climatização para abrigos de equipamentos eletrônico, contemplando o controle dos níveis de umidade, de temperatura e a eliminação de partículas de poeira suspensa no ar. Existe uma ampla gama de tipos de abrigos, como subestações pré-fabricadas, data-centers, shelters de telecomunicação, salas elétricas, dentre outros. Ao abrigar equipamentos elétricos em funcionamento, a quantidade e acumulo de energia térmica no interior do ambiente onde se localizam ocasiona a elevação da temperatura a níveis inaceitáveis ao bom funcionamento dos equipamentos abrigados. Além disso, a umidade e a existência de particulados no ambiente podem causar a deterioração dos componentes eletrônicos. Por esse motivo é inevitável a utilização de um sistema de climatização para proteção desses equipamentos. O ato de refrigerar, desumidificar, purificar e renovar o ar permite o aumento da vida útil dos equipamentos instalados no interior desses abrigos. O projeto desenvolvido neste trabalho para automatização de um sistema de climatização foi aplicado a uma subestação elétrica pré-fabricada para uma indústria do ramo de mineração.Inicialmente realizou-se um estudo das exigências que o sistema de climatização teria que atender. Realizou-se uma modelagem do sistema levando-se em conta os requisitos do projeto e, para que o sistema fosse aplicado em campo, a lógica de programação foi testada em fábrica por meio do software de programação do CLP e posteriormente comissionado antes da entrega final em campo. O teste de campo consistiu em ligar o sistema automatizado de climatização e simular todo o funcionamento e condições de falhas possíveis, certificando que as respostas do sistema estivessem dentro das especificações definidas durante o projeto. O sistema desenvolvido encontra-se em funcionamento e serve de modelo para o desenvolvimento de novos projetos de climatização. / The aim of this study was to develop a system to attend the needs of automation and control of a cooling system for electronic equipment shelters, including the control of humidity, temperature and elimination of dust particles suspended in air. There is a wide range of types of shelters, such as prefabricated substations, data centers, telecom shelters, electrical rooms, among others. In house electrical equipment in operation, the amount and accumulation of heat inside this type o shelters where they are located causes the temperature rise to unacceptable levels for the proper functioning of equipment housed. Moreover, the presence of moisture and particulates in the environment may cause deterioration of electronic components and so it is inevitable to use a cooling system for protection of such equipment. The act of cooling, dehumidify, purify and renew the air permit to increase the lifetime of the equipment installed inside these shelters. The project developed in this work for automation of a cooling system was applied to an electrical substation for a prefab industry mining sector. Initially we carried out a study of the requirements that the HVAC system and would have to attend before the system was applied in the field, the programming logic was tested at the factory through the PLC programming software and subsequently commissioned before final delivery in field. The field test was to connect the automated climate control and simulate the entire operation and fault conditions possible, ensuring that the system responses were within the specifications established during the project. The system is designed for operation and serves as a model for the development of new draft cooling.
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Synthesis of optimum HVAC system configurations by evolutionary algorithmZhang, Yi January 2005 (has links)
The HVAC system configuration is a conceptual design of the HVAC system, including the employed components, the topology of the airflow network, and the control strategy with set points. Selection of HVAC system configuration is normally done in the early stage of the design process. The configuration design, however, has significant impacts on the performance of the final system. This thesis describes the development of the design synthesis of optimal HVAC system configurations by Evolutionary Algorithm. In this research, the HVAC system configuration design synthesis has been formulated as an optimisation problem, in which, the component set of the configuration, the topology of the airflow network, and the control set points for the assumed supervisory control strategy, are the optimisation variables. Psychrometrics-based configuration model has been developed in order to evaluate the optimisation objective of minimising the annual energy consumption of the HVAC system. The optimisation is also subjected to a number of design constraints, including the connectivity of the topology, the performance limitations of the components, and the design requirements for the air-conditioned zones. The configuration synthesis problem is a multi-level optimisation problem. The topology depends on the set of selected components, whereas the search space of the control set points changes with the different components and topology. On the other hand, the performance of the configuration is assessed with its optimum operation; therefore the control set points have to be optimised for each configuration solution, before the optimum configuration can be identified. In this research, a simultaneous evolutionary approach has been developed. All optimisation variables of the configuration have been enwded into an integrated genotypic data structure. Evolutionary operators have also been developed to search the topological space (for the optimum topology) and parametric space (for the optimal control set points) at the same time. The performance of the developed approach has been validated with example optimisation problems. It is concluded that the implemented evolutionary algorithm has been able to find (near) optimum solutions for various design problems, though multiple trials may be required. The limitations of this approach and the direction of future development have been discussed.
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Detection of abnormal situations and energy efficiency control in Heating Ventilation and Air Conditioning (HVAC) systemsSklavounos, Dimitris C. January 2015 (has links)
This research is related to the control of energy consumption and efficiency in building Heating Ventilation and Air Conditioning (HVAC) systems and is primarily concerned with controlling the function of heating. The main goal of this thesis is to develop a control system that can achieve the following two main control functions: a) detection of unexpected indoor conditions that may result in unnecessary power consumption and b) energy efficiency control regarding optimal balancing of two parameters: the required energy consumption for heating, versus thermal comfort of the occupants. Methods of both orientations were developed in a multi-zone space composed of nine zones where each zone is equipped with a wireless node consisting of temperature and occupancy sensors while all the scattered nodes together form a wireless sensor network (WSN). The main methods of both control functions utilize the potential of the deterministic subspace identification (SID) predictive model which provides the predicted temperature of the zones. In the main method for detecting unexpected situations that can directly affect the thermal condition of the indoor space and cause energy consumption (abnormal situations), the predictive temperature from the SID model is compared with the real temperature and thus possible temperature deviations that indicate unexpected situations are detected. The method successfully detects two situations: the high infiltration gain due to unexpected cold air intake from the external surroundings through potential unforeseen openings (windows, exterior doors, opened ceilings etc) as well as the high heat gain due to onset of fire. With the support of the statistical algorithm for abrupt change detection, Cumulative Sum (CUSUM), the detection of temperature deviations is accomplished with accuracy in a very short time. The CUSUM algorithm is first evaluated at an initial approach to detect power diversions due to the above situations caused by the aforementioned exogenous factors. The predicted temperature of the zone from the SID model utilized appropriately also by the main method of the second control function for energy efficiency control. The time needed for the temperature of a zone to reach the thermal comfort zone threshold from a low initial value is measured by the predicted temperature evolution, and this measurement bases the logic of a control criterion for applying proactive heating to the unoccupied zones or not. Additional key points for the control criterion of the method is the occupation time of the zones as well as the remaining time of the occupants in the occupied zones. Two scenarios are examined: the first scenario with two adjacent zones where the one is occupied and the other is not, and the second scenario with a multi-zone space where the occupants are moving through the zones in a cascade mode. Gama and Pareto probability distributions modeled the occupation times of the two-zone scenario while exponential distribution modeled the cascade scenario as the least favorable case. The mobility of the occupants modeled with a semi-Markov process and the method provides satisfactory and reasonable results. At an initial approach the proactive heating of the zones is evaluated with specific algorithms that handle appropriately the occupation time into the zones.
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Quantification of Human Thermal Comfort for Residential Building's Energy SavingSharifani, Pooya 08 1900 (has links)
Providing conditioned and fully controlled room is the final goal for having a comfortable building. But on the other hand making smart controllers to provide the required cooling or heating load depending on occupants' real time feeling is necessary. This study has emphasized on finding a meaningful and steady state parameter in human body that can be interpreted as comfort criterion which can be expressed as the general occupants' sensation through their ambient temperature. There are lots of researches on human physiological behavior in different situations and also different body parts reaction to the same ambient situation. Body parts which have the biggest reliable linear fluctuation to the changes are the best subject for this research. For these tests, wrist and palm have been selected and their temperatures on different people have been measured accurately with thermal camera to follow the temperature trend on various comfort levels. It is found that each person reaches to his own unique temperature on these two spots, when he/ she feels comfortable, or in other word each person's body temperature is a precise nominate for comfort feeling of that individual. So in future by having this unique comfort parameter and applying them to the HVAC system temperature control, controlling the dynamic temperature and correlating the indoor condition depending on the occupants instant thermal comfort level, would be a rational choice to bring convenience while energy has been saved more.
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