• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 5
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 20
  • 20
  • 5
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design of Intelligent Air Conditioner Controller Using Power Line Carrier Technology

Wu, Wei-Jun 06 July 2009 (has links)
This thesis develops a peers-to-peers intelligent air conditioner (A/C) controller which integrates the power line carrier technology and the infrared remote control. The intelligent air conditioner controller is used for the remote temperature setting and load control of air conditioner without requesting extra communication line and modification of the control circuit in the A/C unit. With the A/C controller developed the demand response in residential and commercial areas can be achieved effectively by reducing the peak power demand of A/C units. In order to investigate the PLC signal transmission over the low voltage distribution lines, the mathematical model of low voltage distribution system under high carrier signal frequency is derived. The computer simulation is executed to analyze the transmission characteristics of power line carrier signal. The proposed controller can receive the command issued by the demand response control center over the distribution lines with carrier frequency to execute the remote temperature setting of A/C units. Based on the field measurement of energy by air conditioner, it is found that significantly power demand reduction of air conditioner has been resulted by applying the proposed controller for remote temperature setting of air conditioner.
2

A study of Kaohsiung citizens¡¦ air-conditioning consumption behavior and its precursors

He, Chen-chang 29 August 2006 (has links)
none
3

Sistema de ar condicionado por absorção para ônibus

Martinelli Junior, Luiz Carlos [UNESP] 29 September 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-09-29Bitstream added on 2014-06-13T19:46:36Z : No. of bitstreams: 1 martinellijunior_lc_dr_guara.pdf: 2129598 bytes, checksum: 077cb099a0427f9857575f0eb35c7028 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Máquinas de absorção são dispositivos que produzem frio ou calor útil utilizando como fonte principal o calor residual de processos ou da queima de combustíveis diversos. Estes sistemas de refrigeração podem ser recomendados para aplicações em sistemas de condicionamento de ar de ônibus e caminhões, onde o espaço disponível para a instalação do mesmo é pequeno. Neste trabalho efetua-se o balanço exergético de uma máquina de absorção que utiliza o calor dos gases de exaustão de um motor de combustão interna (diesel) como fonte de energia. Este sistema é aplicado como ar condicionado veicular alternativo. O cálculo baseia-se em sistema aplicado a um ônibus, onde há um grande fluxo de gases de exaustão a elevadas temperaturas. Conclui-se que o calor residual liberado pelo ônibus é suficiente para acionar o sistema de ar condicionado alternativo, e que em termos exergéticos as maiores irreversibilidades estão associadas ao gerador (desorbedor), indicando de certo modo a necessidade de efetuar melhorias neste componente do sistema de absorção. Finalmente a Análise da Eficiência Ecológica é aplicada, considerando o sistema alternativo para um ônibus com motor Mercedez-Benz. A utilização do mesmo possibilita, além de uma visível economia de combustível, a melhoria da eficiência global e ecológica. / Absorption machines are devices that produce useful cold or heat using the residual heat of systems or combustion of several fuels. These absorption refrigeration systems can be recommended for applications in air conditioning systems of buses and trucks, which have a restricted space available for their installation. This work presents the energetic and exergetic balances of an absorption machine that uses the exhaust gases of an internal combustion engine (diesel) as source of energy. Such system is applied as an alternative vehicular air conditioner. The calculation is based on a bus-installed system where a high flow of exhaust gases at high temperatures is produced. It is concluded that the residual heat released by the bus is sufficient to activate the alternative air conditioning system, and that the largest irreversibilities in exergetic terms are associated to the generator (desorber), indicating somewhat the need to accomplish several improvements in this component of the absorption system. Finally the Ecological Efficiency Analysis are applied considering the alternative system to a bus with a Mercedez-Benz Engine. Using that engine enable an economy of combustion and a global and ecological efficiency better.
4

Conforto térmico em edificações

Oliveira, Lidiane Alves de [UNESP] 11 1900 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-11Bitstream added on 2014-06-13T18:59:52Z : No. of bitstreams: 1 oliveira_la_me_guara.pdf: 2784324 bytes, checksum: 076f01bfc4c089c335c41d4360749ebe (MD5) / Este trabalho analisa edifícios que, devido a sua arquitetura moderna, utilizam grande superfície de vidro nas fachadas apresentando, na maior parte das vezes, problemas de conforto térmico. Como objeto deste estudo decidiu-se por um prédio da UNESP, campus de Guaratinguetá. A análise realizada foi baseada no estudo da insolação (diagrama solar), em medidas locais de temperatura, umidade e no levantamento da carga térmica, objetivando avaliar as condições do edifício e propor soluções visando um melhor conforto térmico com a otimização do consumo de energia elétrica. / This work analyzes buildings that, due to their modern architecture, use a great glass surface in the facades presenting, most of the time, problems of thermal comfort. As object of this study we chose a building of UNESP, campus of Guaratingueta. The accomplished analysis was based on the study of the heatstroke (solar diagram), in measuring temperature places, humidity and in the rising of the thermal load, aiming at evaluating the conditions of the building and to propose solutions seeking a better thermal comfort with the optimization of the consumption of electric energy.
5

Parameter Estimation of Dynamic Air-conditioning Component Models Using Limited Sensor Data

Hariharan, Natarajkumar 2010 May 1900 (has links)
This thesis presents an approach for identifying critical model parameters in dynamic air-conditioning systems using limited sensor information. The expansion valve model and the compressor model parameters play a crucial role in the system model's accuracy. In the past, these parameters have been estimated using a mass flow meter; however, this is an expensive devise and at times, impractical. In response to these constraints, a novel method to estimate the unknown parameters of the expansion valve model and the compressor model is developed. A gray box model obtained by augmenting the expansion valve model, the evaporator model, and the compressor model is used. Two numerical search algorithms, nonlinear least squares and Simplex search, are used to estimate the parameters of the expansion valve model and the compressor model. This parameter estimation is done by minimizing the error between the model output and the experimental systems output. Results demonstrate that the nonlinear least squares algorithm was more robust for this estimation problem than the Simplex search algorithm. In this thesis, two types of expansion valves, the Electronic Expansion Valve and the Thermostatic Expansion Valve, are considered. The Electronic Expansion Valve model is a static model due to its dynamics being much faster than the systems dynamics; the Thermostatic expansion valve model, however, is a dynamic one. The parameter estimation algorithm developed is validated on two different experimental systems to confirm the practicality of its approach. Knowing the model parameters accurately can lead to a better model for control and fault detection applications. In addition to parameter estimation, this thesis also provides and validates a simple usable mathematical model for the Thermostatic expansion valve.
6

Sistema de ar condicionado por absorção para ônibus /

Martinelli Junior, Luiz Carlos. January 2008 (has links)
Orientador: José Luz Silveira / Banca: Celso Eduardo Tuna / Banca: Jose Nedilo Carrinho de Castro / Banca: João Manoel Dias Pimenta / Banca: Luiz Francisco Marcon Ribeiro / Resumo: Máquinas de absorção são dispositivos que produzem frio ou calor útil utilizando como fonte principal o calor residual de processos ou da queima de combustíveis diversos. Estes sistemas de refrigeração podem ser recomendados para aplicações em sistemas de condicionamento de ar de ônibus e caminhões, onde o espaço disponível para a instalação do mesmo é pequeno. Neste trabalho efetua-se o balanço exergético de uma máquina de absorção que utiliza o calor dos gases de exaustão de um motor de combustão interna (diesel) como fonte de energia. Este sistema é aplicado como ar condicionado veicular alternativo. O cálculo baseia-se em sistema aplicado a um ônibus, onde há um grande fluxo de gases de exaustão a elevadas temperaturas. Conclui-se que o calor residual liberado pelo ônibus é suficiente para acionar o sistema de ar condicionado alternativo, e que em termos exergéticos as maiores irreversibilidades estão associadas ao gerador (desorbedor), indicando de certo modo a necessidade de efetuar melhorias neste componente do sistema de absorção. Finalmente a Análise da Eficiência Ecológica é aplicada, considerando o sistema alternativo para um ônibus com motor Mercedez-Benz. A utilização do mesmo possibilita, além de uma visível economia de combustível, a melhoria da eficiência global e ecológica. / Abstract: Absorption machines are devices that produce useful cold or heat using the residual heat of systems or combustion of several fuels. These absorption refrigeration systems can be recommended for applications in air conditioning systems of buses and trucks, which have a restricted space available for their installation. This work presents the energetic and exergetic balances of an absorption machine that uses the exhaust gases of an internal combustion engine (diesel) as source of energy. Such system is applied as an alternative vehicular air conditioner. The calculation is based on a bus-installed system where a high flow of exhaust gases at high temperatures is produced. It is concluded that the residual heat released by the bus is sufficient to activate the alternative air conditioning system, and that the largest irreversibilities in exergetic terms are associated to the generator (desorber), indicating somewhat the need to accomplish several improvements in this component of the absorption system. Finally the Ecological Efficiency Analysis are applied considering the alternative system to a bus with a Mercedez-Benz Engine. Using that engine enable an economy of combustion and a global and ecological efficiency better. / Doutor
7

Conforto térmico em edificações /

Oliveira, Lidiane Alves de. January 2003 (has links)
Orientador: Luiz Roberto Carrocci / Banca: Felipe Rinaldo Queiroz de Aquino / Banca: Luiz Octávio Mattos dos Reis / Resumo: Este trabalho analisa edifícios que, devido a sua arquitetura moderna, utilizam grande superfície de vidro nas fachadas apresentando, na maior parte das vezes, problemas de conforto térmico. Como objeto deste estudo decidiu-se por um prédio da UNESP, campus de Guaratinguetá. A análise realizada foi baseada no estudo da insolação (diagrama solar), em medidas locais de temperatura, umidade e no levantamento da carga térmica, objetivando avaliar as condições do edifício e propor soluções visando um melhor conforto térmico com a otimização do consumo de energia elétrica. / Abstract: This work analyzes buildings that, due to their modern architecture, use a great glass surface in the facades presenting, most of the time, problems of thermal comfort. As object of this study we chose a building of UNESP, campus of Guaratingueta. The accomplished analysis was based on the study of the heatstroke (solar diagram), in measuring temperature places, humidity and in the rising of the thermal load, aiming at evaluating the conditions of the building and to propose solutions seeking a better thermal comfort with the optimization of the consumption of electric energy. / Mestre
8

Study on solar driven office cooling system

Almouayad Alazm, Zafer January 2019 (has links)
No description available.
9

Design and Implementation of an Air Conditioner Adaptive Compressor Driver with Sine PWM and Current Feedback

Hung, De-Shian 27 October 2010 (has links)
This thesis uses TMS320LF2407A DSP from T.I. as the control kernel .It proposes a method of sensorless driver and variable speed driver with current feedback for the rotary compressor. By detecting the back electromotive force signals, the information of rotor position can be detected by the commutation process and the speed estimation can also be achieved. In order to make the system more robust and the improve the power consumption, adaptive controller and close loop structure are adapted. At last, the experimental system structure is built, and the advantages improvement efficiency of the system with sensorless driver¡Bspeed and current feedback were be verified by experiment.
10

Design of Shunt Semi-Active Power factor Correction Circuits

Chen, Bing-Hao 14 February 2012 (has links)
This study aims to design a Shunt Semi-Active Power Factor Correction Circuits , which can be applied to high power circuit by low switching frequency. The designed circuit can avoid power loss working with high switching frequency when using the method of active power factor correction .The experimental configuration based on DSP is applied to a compressor of air conditioner with varied load. The simulation check the developed circuit using Ispice . Both of the experimental and simulation results have guaranteed the derived configuration reach the expected goals.

Page generated in 0.1067 seconds