Results 1 - 10 of 14
Results 1 - 10 of 14. Search took: 0.015 seconds
|Sort by: date | relevance|
[en] In China, the area of existing buildings in urban and rural has exceeded 43 billion m2 at present and more than 90% of them are high energy consumption buildings, which have poor thermal insulation performance, low energy efficiency technologies and equipments, and severe energy waste in HVAC system. Carbon trading in construction field not only promotes energy efficiency retrofit of existing buildings and energy-saving technologies, but also reduces the financial pressure of government. The most important technical issue is how to estimate the carbon trading volume reasonably. Based on the requirements of energy efficiency retrofit of existing buildings, relevant national or professional standard standards and CDM small scale project methodologies, this paper puts forward a simplified and practical method of checking and certifying the carbon trading volume of existing buildings retrofits in China and calculates four typical cases for trail. Moreover, a comprehensive methodological framework is presented to make the method guide actual cases more directly and apparently. The framework comprises project analysis, scenario determination, data collection and envelope calculation. - Highlights: • Method of calculating carbon trading volume (CTV) of existing buildings retrofit. • Analyze calculation method of CTV for public buildings and residential buildings. • The corresponding case analyses are provided. • Method involves applicability, boundary, emission, emission reduction, and monitoring
[en] Highlights: • A solar seasonal storage coupled with ground source heat pump system was designed and implemented. • The COP of GSHP system and coupled system were calculated and compared. • The COP of the coupled system was higher than that of GSHP system. • The soil temperature increased after solar seasonal storage process. - Abstract: The COP (Coefficient of Performance) of the ground-source heat pump (GSHP) system decreased gradually year after year mainly caused by imbalance of thermal energy inputting, especially in heating-dominated climate zones. An experimental system of solar seasonal storage coupling with ground-source heat pump was designed and implemented. This system was installed in a group of new buildings of the new campus in Tianjin, China, which is located in cold climate zone and heat demand is dominated. To make evaluation to this system, a mathematical method was developed to calculate the COP of GSHP system and the coupled system. In this thermal storage experiment process, a system with 1500 m"2 solar thermal collectors and 580 sets of 120 m deep ground thermal exchangers was involved in this research. Results show that the soil temperature has not descended but increased by 0.21 °C, and the COP of system and heat pump unit increased 3.4% and 2.4% respectively compared to the operation data without solar seasonal storage process during last year. Although the effectiveness of solar seasonal storage coupled is not conspicuous as expected during the testing period, it indicates that the tendency of COP declination is prevented, and further illustrating that improving the COP of the system is a long-term work, the application of solar seasonal storage coupled with GSHP system should be encouraged for long-term operation
[en] Highlights: • An assessment method considering economy, environment and technology is proposed. • Office buildings are classified into 3 types and weights are calculated respectively. • BESTs were summed up as 3 suitability levels. • Recommendations are proposed for adopting in design stage. - Abstract: Blind application and extensive copy of building energy saving technologies have been found very common through investigation in China. Emphases should be put on the suitability assessment when selecting and optimizing building energy saving technologies. This paper created an assessment method, namely an assessment framework to assess the suitability level of building energy saving technologies from a holistic point of view. Fuzzy analytic hierarchy process was adopted. 3 factors and 8 sub-factors were included in the framework. The office buildings were classified into 3 types to calculate weights of factors and sub-factors. The assessment framework was established for each type of office buildings. 20 energy saving technologies from surveyed cases was selected as case study. Ranks of suitability level of the assessment objects were obtained for each type of office buildings. The assessment results could be referred when selecting building energy saving technologies in the design stage
[en] Highlights: • A modified bin method is adopted to propose and optimize the EER schemes. • A case study is presented to demonstrate the analysis procedures of EER schemes. • Pertinent EER schemes for HVAC systems are proposed for the object building. - Abstract: Poor thermal performance of building envelop and low efficiencies of heating, ventilating and air-conditioning (HVAC) systems can always be found in the existing office buildings with large energy consumption. This paper adopted a modified bin method to propose and optimize the energy efficiency retrofit (EER) schemes. An existing office building in Tianjin was selected as an example to demonstrate the procedures of formulating the design scheme. Pertinent retrofit schemes for HVAC system were proposed after the retrofit of building envelop. With comprehensive consideration of energy efficiency and economic benefits, the recommended scheme that could improve the overall energy efficiency by 71.20% was determined
[en] Although GSHPs (ground-source heat pump system) have already drawn a fair amount of attention in China because of its high energy efficiency and low environmental impact characteristics, some practical problems appeared much more than the expected. COP (Coefficient of Performance) of the GSHPs decreased gradually year after year caused by imbalance energy loads especially in heating-dominated climate zones. So an experiment of solar seasonal storage coupling with GSHP was designed and implemented. In this thermal storage experiment process, a system with 1500 m solar thermal collectors and 580 sets of 120 m deep ground thermal exchangers were taken into research. Thermal equilibrium of soil was studied; relationship between solar energy radiation quantity and thermal storage quantity was discussed. Results showed that solar energy utilization efficiency achieved 50.2% and soil temperature raised by 0.21 °C. TRNSYS 16 was used to simulate thermal storage experiment, and simulation results were well matched with the measured data. - Highlights: • Thermal equilibrium for solar seasonal storage system was studied. • The solar heat storage system based on ground-source heat pump. • Solar heat storage experiment was performed. • The solar heat storage process was simulated by TRNSYS 16.
[en] Heat metering and energy efficiency retrofit of existing residential buildings in northern heating areas of China is organized and implemented in a large scale by local government in 15 provinces of North China with the unified guidance and control of central government. Firstly, this paper introduced the target of energy-saving reformation of existing residential buildings in North China and the importance of check and evaluation on this target, then pointed out the necessity of building up an evaluation system for energy-saving retrofit. According to the analytical hierarchy process (AHP), three-grade evaluation system was built up for heat metering and energy efficiency retrofit of existing residential buildings in northern heating areas of China. Also, based on multi-index comprehensive evaluation method combined with life cycle assessment (LCA) theory, post-evaluation thought and successful degree evaluation method, a mathematical model was established. Finally, a set of scientific method for evaluating heat metering and energy efficiency retrofit of existing residential buildings in northern heating areas of China systematically, scientifically, comprehensively and objectively was created.
[en] Highlights: • Subentry electricity consumption is considered for campus building benchmarks. • New methods of electricity benchmarking for complex campus buildings are proposed. • A rating system is established based on new benchmarks. - Abstract: Publicising the energy consumption of buildings is an effective way to promote building energy efficiency in colleges and universities. The aim of this study is to propose a method for developing electricity benchmarks for complex campus buildings. This study uses various statistical methods to determine such benchmarks. The determination of new electricity benchmarks includes the following steps: (a) determination of the factors influencing electricity consumption, (b) standardisation of indicators, and (c) calculation and correction of the electricity benchmarks. Thirteen complex buildings from the hot summer and cold winter zone of China were selected as samples to illustrate the standardisation process. The total electricity and subentry electricity benchmarks are determined based on multiple linear regression analyses. Multi-factor analyses of variance were used to identify the categorical factors that have significant influences on electricity consumption and on the correction of benchmarks. Finally, a rating system for the evaluation of electricity consumption was also established that applied the corrected electricity benchmarks.
[en] In China, northern heating region contains approximately 6.5 billion m2 residential building areas accounting for 15% of the total residential living areas of urban and rural. About 70% of the urban residential buildings in north China are high energy consumption buildings. The task of heat metering and energy efficiency retrofit of 0.15 billion m2 existing residential buildings in northern heating areas of China in “the 11th Five-Year Plan” period was proposed by the Ministry of Housing and Urban–Rural Development (MOHURD) in 2007 and completed in 2010. This paper introduced both central and local governments' efforts on organization, implementation and finance, etc. Then several retrofitting effects involving improving the people's livelihood, mobilizing the enthusiasm of residents for the retrofit and driving the development of relevant industries were presented. Finally, on the basis of analyzing the issues encountered in the progress of the retrofit in the past 4 years, the paper gave some policy proposals on organization system, financing models, reward mechanism, and heating system reformation to help to promote the energy efficiency retrofit in “the 12th Five-Year Plan” period. - Highlights: ► Specific approaches of heat metering and energy efficiency retrofit (HMEER) at central and local level are introduced. ► Main HMEER effects are presented. ► Analyzing several issues encountered in the progress of the HMEER. ► Corresponding proposals are provided.
[en] According to statistics and field investigation, the energy consumption situation and reality of commercial building is described in this paper. As the first step of large-scale public building energy efficiency supervision system encouraged by central government of China, the energy consumption of several typical commercial buildings and public buildings was analyzed in detail. The main contents of investigation are as follows: basic information of building, operational record of energy consumption equipment, energy consumption of indoor equipments, energy-efficiency assessment of energy consumption systems and equipments, investigation of behavior energy saving, etc. On this basis further analysis and diagnosis including indoor thermal and humid environment, operation state of air-conditioning water system, operation state of air-conditioning duct system and operation management of air-conditioning system were implemented. The results show that the most energy consumption of buildings in this city is commercial buildings, which can reach to about 240 W/m2 per year. Further analysis tells that air conditioning systems play the major role of building energy consumption, and building energy saving has great potential in this city. In this paper, the ways of diagnosis work for building energy consumption are also described and discussed. Reasonable test, diagnosis and analysis are meaningful for building energy efficiency retrofit and management.
[en] The Chinese central government released a document to initiate a task of energy efficiency supervision system construction for government office buildings and large-scale public buildings in 2007, which marks the overall start of existing buildings energy efficiency management in China with the government office buildings and large-scale public buildings as a breakthrough. This paper focused on the implementing effect in the demonstration region all over China for less than one year, firstly introduced the target and path of energy efficiency supervision system, then described the achievements and problems during the implementing process in the first demonstration provinces and cities. A certain data from the energy efficiency public notice in some typical demonstration provinces and cities were analyzed statistically. It can be concluded that different functional buildings have different energy consumption and the average energy consumption of large-scale public buildings is too high in China compared with the common public buildings and residential buildings. The obstacles need to be overcome afterward were summarized and the prospects for the future work were also put forward in the end.