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  • 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

Potential advantages of applying a centralized chilled water system to high-density urban areas in China

Kang, Di January 1900 (has links)
Master of Science / Department of Architectural Engineering and Construction Science / Fred L. Hasler / This paper discusses the advantages of applying a utility centralized chilled water system as the district cooling choice for facilities in the high-density urban areas of China and how it will influence China’s development in the next decades. Presently, the Chinese government is trying to contribute to the world’s energy-saving goals as well as determine its sustainable development framework. As air pollution has become one of the main problems in China, indoor air quality (IAQ) is likely to gain priority as a building design consideration in the future. Consistent with this fact, this paper proposes an optimum HVAC system for cooling purposes to the Chinese government. Compared to unitary HVAC systems, the centralized HVAC system has significant advantages in system efficiency, energy reduction and cost savings and can, therefore, be a better choice. Furthermore, the paper will focus on the centralized chilled water system and demonstrate why they better match the development model in China. The application of the system in high-density urban areas will also be discussed. Due to a lack of understanding that the energy consumption of unitary systems, the first comparison presented is between unitary HVAC systems and centralized HVAC systems in individual buildings. The comparison presented will focus on the energy-saving benefits of the centralized HVAC system in individual buildings and its contribution to sustainable development. Consequently, prescribing a centralized chilled water system as a utility district cooling system and applying a centralized chilled water system to each individual building in the highdensity urban areas will be compared. Cost savings, including initial cost and life cycle cost, are the metrics used in this comparison. Additionally, energy consumption and system reliability will be explored in determining which model will be more appropriate for China's development. The paper concludes that the centralized chilled water system should become the mainstream in the high-density urban area in China. Several recommendations are also made to the Chinese government on setting up utility centralized chilled water systems.
2

Development of an energy monitoring and targeting methodology for the most efficient operation of chilled water systems : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Energy Management at Massey University, Palmerston North, New Zealand

Vaino, Federica January 2008 (has links)
The increasing price of oil and the destabilisation of the world’s climate are urging governments, businesses and individuals to constantly investigate energy-efficient technologies and methodologies and pursue the adoption of energy efficiency programmes in a global effort to reduce energy consumption, greenhouse gas emissions and ultimately energy costs. In New Zealand, one of the biggest industrial energy efficiency projects was started in 2002 by a multinational dairy company, the Fonterra Co-operative Group, in partnership with the energy service company Demand Response Ltd; the project currently aims at reducing by 15% the energy costs at all Fonterra’s major production sites throughout the country. This thesis, undertaken as part of the above project, examines the development and implementation of a structured and integrated energy monitoring and targeting methodology (M&T) for the most efficient operation of all Fonterra’s chilled water systems, with an initial focus on the ones installed at Clandeboye, one of the Fonterra’s sites involved in the energy saving project. A data collection system (Insite) was already in place at Clandeboye to enable storage and analysis of some of the site’s utility metering data. After identification of key chilled water system components and definition of data requirements for M&T purposes, an analysis of past energy consumption trends (based on multiple regression calculations) was carried out to develop an historical benchmark of the energy used, compare it with current energy performance and thus identify opportunities for future improvements. The creation of an M&T reporting system for presenting findings to operators and management was the last essential part of the thesis development. The study has highlighted that the robustness of the proposed regression model was badly affected by the unreliability of the existing data collection system and the uncertainty associated with poorly documented changes to operating conditions/plant configuration that had occurred over time. The conclusion is that, while the developed M&T methodology is theoretically valid and readily applicable, further developments are necessary (and recommended) to make it suitable for other similar systems.
3

Low energy air conditioning for hot climates

Almutairi, Hamad Hhn January 2012 (has links)
Fossil fuels are the major sources of electrical power generation in the world. Among all fossil fuels, oil is considered as the most sought-after fuel. The burden on countries that provide subsidized electricity produced from oil-fired power plants is noteworthy. Kuwait is a notable example of these countries. Electricity in Kuwait is heavily consumed by residential air conditioning, which comprises 60% of the total electricity generated at peak times on a hot summer day. From this perspective, residential air conditioning in Kuwait was selected to undergo further investigation regarding low energy air conditioning choices. Three solutions to control the rapid growth of demand for electricity by residential air conditioning are examined. The first solution investigated assesses the orientation and grouping of houses in Kuwait in order to examine their effect on cooling load and electrical energy consumption for future houses. Four residential cases were developed; each case comprises six typical houses. The cases identified are: (1) single block facing east-west, (2) single block facing north-south, (3) double block facing east-west and (4) double block facing north-south. Cooling loads are calculated using the DesignBuilder building thermal simulation software. Case (2) is found to have the smallest cooling load, and case (1) the largest. The estimated savings from applying case (2) compared to the average of the four cases for the future houses planned to be built by the government by the year 2016 (i.e. approximately 20,000 houses) are found to be approximately .US 33 million of power system capital costs, 15 GWh per year of electrical energy consumption and 11 kilotons per year of CO2 emissions. In the second solution, a lifecycle cost analysis is performed to evaluate the economic feasibilities of electricity driven chilled water system compared to predominant air conditioning system in Kuwaiti houses which is Packaged- Direct Expansion. The study considers the total cash paid by the consumer and the total cash paid by the government, since electricity is subsidized in Kuwait. The study finds that the chilled water system is not cost-effective for consumers due to high installation cost. However, a chilled water system would be cost-effective for the government because it consumes 40%less electrical energy than Packaged-DX. So, the study suggests subsidising the installation of chilled water systems so that the installation cost to the consumer is the same as for Packaged-DX systems. In the third solution, the study examines the viability of a single-effect LiBr absorption chiller driven by steam extracted from the steam turbine in the configuration of a combined cycle power plant (CCPP). The analysis shows that CCPP with absorption chiller yields less net electrical power available to utility grid compared to similar CCPP giving electricity to the grid and to Direct-Expansion air conditioning systems for the same cooling requirements. The reasons for that are the reduction in steam turbine power output resulted from steam extraction, and the amount of electrical energy required to operate the configuration of CCPP with absorption chiller.

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