共查询到20条相似文献,搜索用时 15 毫秒
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The dome-covered house is an example of designing buildings by learning from the optimized biological forms from the nature in order to reduce the energy use for heating in cold climates. This paper presents the three-dimensional thermal and airflow (3D-TAF) model that predicts the impact of such dome on the heating load of the protected house. The emphasis is on the airflow model, the formulation of the system of equations, the calculation procedure, and the comparison with a CFD model. A case study of a dome located in Montreal (Canada) is presented. A linear correlation model is developed that predicts the variation of the dimensionless air temperature inside the dome with the dimensionless height. 相似文献
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Mats Sandberg 《Building and Environment》1984,19(4):221-233
A general multichamber model is presented and explored from the viewpoint of air quality studies. The model involves the following key concepts: purging flow rate and age distribution of both air and contaminants. From the physical and mathematical properties of the model, are deduced estimates of the magnitude of, and the relations between, the key concepts. The practical use of the model is illustrated. 相似文献
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An evaluation model for individual thermal comfort is presented based on the BP neural network. The train data came from a thermal comfort survey. The evaluation results of the model showed a good match with the subject's real thermal sensation, which indicated that the model can be used to evaluate individual thermal comfort rightly. Taken a room air conditioner as an example, the application of the NNEM in creating a microenvironment for individual was discussed. The result showed that the NNEM can play an important role of connecting individual thermal comfort with the control on the air conditioner. 相似文献
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《Journal of Building Performance Simulation》2013,6(5):326-337
The TRNSYS energy analysis tool has been capable of simulating whole-building coupled heat transfer and building airflow for about 10 years. The most recent implementation was based on two TRNSYS modules, Type 56 and Type 97. Type 97 is based on a subset of the airflow calculation capabilities of the CONTAM multizone airflow and contaminant transport program developed by the National Institute of Standards and Technology. This paper describes the development of new CONTAM capabilities in support of an updated combined, multizone building heat transfer, airflow and contaminant transport simulation approach using TRNSYS. It presents an illustrative case that highlights the new coupling capability and also presents the application of this coupled simulation approach to a practical design problem of the energy use related to airflow through entry doors in non-residential buildings. 相似文献
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The zero-equation turbulence model for indoor airflow applications proposed by Chen and Xu [4] has obtained immense popularity amongst the CFD practitioners in HVAC industry. A uniform turbulent intensity of 10% has been assumed in their model. In this paper, following the analogy of Chen and Xu [4] in deriving the coefficient of their zero-equation turbulence model (0.03874) which is indeed expressed as a function of turbulent intensity, the effect of turbulent intensity value assumed in the model towards the solution accuracy is investigated in this paper. Three indoor airflow cases, i.e. forced convection, natural convection and mixed convection problems are studied. It has been discovered that as the assumed uniform turbulent intensity Ti is reduced, the solution accuracy is significantly improved and the prediction comes closer to those of the two-equation standard k-? model, LES model as well as the experimental data. 相似文献
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结合路基施工中振动压路机选型的实践,以属性数学理论建立振动压路机选型综合评价的属性测度模型。实例研究表明,该模型评价结果合理,计算过程简便,并且还可用于振动压路机的工程适用性、经济性和可靠性的综合评价中。 相似文献
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结合路基施工中振动压路机选型的实践,以属性数学理论建立振动压路机选型综合评价的属性测度模型。实例研究表明,该模型评价结果合理,计算过程简便,并且还可用于振动压路机的工程适用性、经济性和可靠性的综合评价中。 相似文献
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Development and identification of an integrated waterworks model for trihalomethanes simulation 总被引:1,自引:0,他引:1
To evaluate the impact that new trihalomethanes (THMs) regulations will have on the performance of conventional waterworks in China, we developed an integrated waterworks model to simulate the dynamic behavior of THMs and other associated components, e.g. organic matter, ammonia, and residual chlorine, throughout the conventional water treatment process, which included pre-chlorination, coagulation-flocculation, sedimentation, filtration and post-chlorination. A comprehensive kinetic scheme that takes into account both the physical and biological mechanisms involved in the water treatment processes and the chemical reactions that result from chlorination was proposed for model conceptualization. In addition, the Petersen matrix was designed to present the model and formulate the mass balance equations for the model variables. The model was then identified using the Hornberger-Spear-Young (HSY) algorithm and tested against field data from the Qingzhou Waterworks in Macao, China. Despite gross uncertainty associated with the field data, the model could generally provide good predictions of the simulated variables and meet the management purposes. Furthermore, the identified model parameters agreed well with values that were reported in the literature and could be reasonably interpreted. 相似文献
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The SST k–ω based model is applied to calculate air-flow velocities and temperatures in a model office room. Calculations are compared with experiments and with the results of the standard k–ε, the RNG k–ε model and the laminar model. It is concluded that (a) all the three tested turbulent models predict satisfactorily the main qualitative features of the flow and the layered type of temperature fields and (b) computations with the SST k–ω based model show the best agreement with measurements. The use of this model is proposed combined with a suitable grid. 相似文献
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The airflow around a building is in high Reynolds number flow regime. It can be calculated by large eddy simulation method (LES). The air temperature around buildings is passive scalar. If the behavior of passive scalars is considered with sub-grid scale (SGS) model for LES, the calculation or the results will be improved greatly but it has not been implemented, till now. In this paper a passive scalar SGS model (PS-SGS) was derived based on the hypotheses about the sheet-like structure in Taylor scale. The kinetic-energy SGS model was improved with the derived PS-SGS. The validity of the model was checked out using the experimental data in reference. The field around a supposed two-dimensional building was estimated with the improved kinetic-energy SGS model. Karman vortex-street and some special behavior for passive scalars were distinguished with the derived model. 相似文献
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Jae-Weon Jeong Joseph Firrantello James D. Freihaut William P. Bahnfleth Amy Musser 《Building and Environment》2008
The feasibility of wireless measurements for rapid tuning of a multizone airflow model was extensively investigated using a small-scale residential building as a test site. The main objective of the research was to provide fundamental information, such as measurement time and cost for various measurement techniques, needed for selecting an appropriate field measurement strategy. Potential advantages of the wireless measurement approach were evaluated. These include: portability and flexibility, fast equipment setup, time synchronized data collection, negligible interruption to the occupants’ activity during the measurement, and installation time and cost savings. Currently, the high equipment cost of the wireless approach, relative to more conventional techniques, may offset the noted advantages and be the highest barrier to the wide use of wireless sensors in field measurements. Consequently, conventional hand-held measurements can be more economical, but the stability of the building HVAC system operating status should be considered before selecting the hand-held measurement approach. System stability and the ambient and internal building load status to which it is responding have significant impact on the model tuning usefulness of this approach 相似文献
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针对水压致裂测量地应力理论与工程研究现状,对水压致裂测量地应力理论、方法、技术以及特点进行了分析,并对水压致裂测量地应力的测量结果进行了论述。 相似文献
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María I. Montoya Elsa Pastor F. Rémi Carrié Gaelle Guyot Eulàlia Planas 《Building and Environment》2010
In this study we estimate the air leakage distribution of single-family dwellings in Catalonia and use a statistical analysis of an airtightness database for single-family dwellings in France to identify the building characteristics that have the greatest influence on airtightness. The most significant variables are found to be the structure type, the floor area, the age of the building, the number of stories and the insulation type. A multiple linear regression technique is then applied to establish a predictive model for deriving an estimated value of airtightness from these characteristics. To estimate the infiltration airflow, a stochastic simulation of the building characteristics was performed per census tract using real data on the distributions of building variables taken from the census information. The model is then applied to determine the power law coefficient and the airtightness distribution. The predicted flow coefficients are combined with the AIM-2 model and given meteorological conditions to determine the infiltration airflow. Two sets of meteorological conditions are considered: average conditions and extreme conditions for each season. 相似文献
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气流运动及其与热舒适关系研究的进展与评述 总被引:23,自引:2,他引:21
指出气流组织的研究对空调节能和保证人体舒适感有着重要的意义,综述了气流运动与热舒适关系及房间气流紊流特征的研究进展,评价了已有的研究成果,对该研究的发展提出了看法。 相似文献