Empirical validation of the thermal model of a passive solar cell test

The paper deals with an empirical validation of a building thermal model. We put the emphasis on sensitivity analysis and on research of inputs/residual correlation to improve our model. In this paper, we apply a sensitivity analysis technique in the frequency domain to point out the more important parameters of the model. Then, we compare measured and predicted data of indoor dry-air temperature. When the model is not accurate enough, recourse to time–frequency analysis is of great help to identify the inputs responsible for the major part of error. In our approach, two samples of experimental data are required. The first one is used to calibrate our model, the second one to really validate the optimized model.     

Evolution and validation of a thermal probe model

This article describes the progress on the modelling of a thermal probe apparatus for in situ measurement of the thermal properties of construction materials, using the commercial heat transfer simulation program Voltra. The article describes the evolution from a model representing a theoretical line source to a model representing a two-dimensional elementary thermal probe. The new model uses a more dense spatial grid. The results of simulations modelling a solid stainless steel probe, and a stainless steel shell filled with glass inserted into stabilized water (agar), glycerine with fibre, toothpaste and polytetrafluoroethylene (PTFE) are described. These models are validated using data obtained through recent laboratory studies; continuity with the earlier work is demonstrated. Comparison of simulation results with experimental data confirms that percentage errors for conductivity and diffusivity are lowest for the model of the glass-filled probe.     

Calibration and experimental validation of a dynamic model of the train-track system at a culvert transition zone

This article describes the calibration and experimental validation of the dynamic model of the train-track system at a culvert transition zone. The dynamic analyses were performed explicitly using a 3D model in LS-DYNA software and implicitly using a 2D model on ANSYS software. In both programmes, contact algorithms were employed to take the wheel-rail interaction into account. The parameters for the 3D model were calibrated based on the track receptance test. The 3D model was used for the static and dynamic calibration of the 2D model. The damping adopted in the 2D model was significantly amplified to compensate for the radiation damping in the transverse direction of the track, which cannot be incorporated in a plane model. An excellent agreement was obtained between the vertical displacements of the rail, the vertical accelerations of the sleepers and the wheel-rail interaction forces computed by the two models. The computation time of the 2D model is about 25 times lower than the computation time of the 3D model. The 2D model was used to simulate the passage of the Alfa Pendular train at 220 km/h at the transition zone and a very good match between measured and computed responses has been obtained.     

Control-oriented model of a solar community with seasonal thermal energy storage: development,calibration and validation

The development of a control-oriented model of a solar community with seasonal storage (the Drake Landing Solar Community) is investigated. The proposed approach, intended to facilitate the development and testing of control strategies and targeting an actual predictive control implementation, is based on grey-box models, and enables the prediction of the system state (temperatures at key locations). This paper discusses the concept of state update procedure (whereby the system state is periodically corrected with measurements), which plays a fundamental role for control purposes. Firstly, the DLSC is presented and both operation and monitoring system are described. Secondly, a simplified model is developed for each sub-system: district and solar loops, short-term (water tanks) and seasonal (borehole) thermal energy storage, and existing operation rules are encoded. Finally, the model is calibrated and validated by using measurements at 10-min intervals over two years of operation (2015–2016, 2016–2017) and accurately predicts the system performance.     

Analytical and inter-program validation of a building thermal model

Results from the analytical and inter-program validation of a building thermal model (CBS-MASS) are presented. Within the analytical validation, the analytical solutions of the steady-state and the transient heat transfer through the exterior walls of an intermediate floor room are compared with the predictions of the computer program. The analysis of the transient process concerns the response of the room air temperature and the inside surface temperature of walls subjected to step-function change of outdoor conditions. Good agreement between the analytical solutions and the simulation results indicates that the basic heat transfer processes are well simulated by the computer program. The inter-program validation deals with the comparison between the estimations of the space thermal loads in one office space provided by the CBS-MASS program against the predictions of two well-known programs used in the thermal analysis of buildings: BLAST and TARP. The results show good agreement between the predictions of these programs. Hence, the analytical and inter-program validation indicates that the CBS-MASS program provides good estimation of the thermal behavior of buildings.     

Calibration and validation of a dynamic model for water quality in combined sewer retention tanks

As the integrated management of urban wastewater systems becomes more and more popular, the development of wastewater management subsystem models appears essential to improve the understanding of the pollutant dynamics and their interactions. In such a context, a review of the literature reveals a lack of efficient models describing the dynamics of the water quality stored in off-line retention tanks. A model has thus been proposed based on the fractionation of suspended solids into three classes according to the particle settling velocity distribution measured in the field using the ViCAs settling test. In this paper, a calibration methodology is developed and full-scale field data sets from three different events are used for 1) calibrating this new dynamic retention tank model (two data sets); and 2) validating that model on the last data set. The results show a good agreement between observed and simulated data both for the total suspended solids and the total chemical oxygen demand.     

内融冰蓄冰桶动态特性模型的建立及验证

介绍了为预测内融冰蓄冰桶动态特性而建立的数学模型用于模拟蓄冷和放冷期间动态特性的计算机程序。预测结果与实验结果吻合良好。     

太阳能光伏光热联合热泵系统研究

本文介绍一种使用普通商用太阳能电池改装的PVT组件,并以此为基础建立光伏光热联合热泵实验系统。通过理论计算和实际测量,分析该系统电效率、热效率与温度之间的关系。结果表明,联合热泵系统能够同时提高太阳能电池光伏转换效率和热泵效率。     

Experimental validation of thermal model of open roof pond

This note presents a simple periodic thermal model for the performance of an open roof pond. The results of this model are seen to be in good agreement with experiment.     

Enhancement of solar thermal energy storage performance using sodium thiosulfate pentahydrate of a conventional solar water-heating system

The time variations of the water temperatures at the midpoint of the heat storage tank and at the outlet of the collector in a conventional open-loop passive solar water-heating system combined with sodium thiosulfate pentahydrate-phase change material (PCM) were experimentally investigated during November and then enhancement of solar thermal energy storage performance of the system by comparing with those of conventional system including no PCM was observed. It was observed that the water temperature at the midpoint of the storage tank decreased regularly by day until the phase-change temperature of PCM after the intensity of solar radiation decreased and then it was a constant value of 45 °C in a time period of approximately 10 h during the night until the sun shines because no hot water is used. Heat storage performances of the same solar water-heating system combined with the other salt hydrates-PCMs such as zinc nitrate hexahydrate, disodium hydrogen phosphate dodecahydrate, calcium chloride hexahydrate and sodium sulfate decahydrate (Glauber's salt) were examined theoretically by using meteorological data and thermophysical properties of PCMs with some assumptions. It was obtained that the storage time of hot water, the produced hot water mass and total heat accumulated in the solar water-heating system having the heat storage tank combined with PCM were approximately 2.59–3.45 times of that in the conventional solar water-heating system. It was also found that the hydrated salts of the highest solar thermal energy storage performance in PCMs used in theoretical investigation were disodium hydrogen phosphate dodecahydrate and sodium sulfate decahydrate.     

旭格太阳能与建筑一体化：光热篇

化石能源的消耗导致二氧化碳的不断排放对气候变化的影响越来越明显,为了保护地球生物生存的环境并为子孙后代留下一些宝贵的自然资源,人类在不断开发利用清洁能源来替代化石能源,太阳能作为一种无污染、几乎永不枯竭的能源而成为当今时代最有发展前景的清洁能源。     

Calibration, validation and sensitivity analysis of an ecosystem model applied to artificial streams

There is a growing interest for the use of ecological models to improve the Ecological Risk Assessment (ERA) of toxic pollutants. However, although several models have been proposed, there is little information available on their relevance (i.e., validation through comparison with original data) and on their sensitivity to the input parameters. In this study, the Aquatox Model was used to simulate biomass dynamics of various biological compartments in artificial streams designed for measuring the effects of pollutants on aquatic communities. Calibration and validation of the model were performed using data from control streams. Multi-variate sensitivity analysis was implemented to identify those parameters that exert a prominent role in the outputs of the model. The calibrated model was able to adequately describe the dynamics of most of the simulated biological compartments of a stream. Using data from other streams, it was shown that between-streams natural variability was a source of discrepancy between observed and simulated data. Sensitivity analysis showed that the model was highly sensitive to the parameters related to the temperature limitation, maximum rate of photosynthesis of producers and consumption by consumers. This strongly suggests that particular attention should be devoted to the estimation of these parameters if this model has to be used for ERA of toxicants in aquatic ecosystems.     

建设工程招投标阶段造价控制探讨

招投标是建立公开、公平、公正和诚实信用的市场秩序的有效手段,也是开展资源节约型经济活动,实现资源配置,提高资产投资效益的重要途径。本文即通过分析建设工程招投标的特点及招投标阶段对工程造价的影响,提出在招投标阶段涩制工程造价应采取的措施,从而达到有效控制工程造价的目的。     

Three dimensional study for evaluating of air flow movements and thermal comfort in a model room: Experimental validation

This paper presents the results of a three dimensional study for evaluating the temperature profiles and air flow movement in a model room with a numerical model based on the Euler equations. Numerical results obtained for two scenarios of ventilation and air conditioning are compared with the predictions of a Navier-Stokes model. These numerical results are validated by experimental results measured in the model room. A comparison of the local thermal comfort indices PMV and PPD obtained experimentally and numerically is also presented. Results show that the Euler model is able to predict adequately total thermal comfort in the model room. Furthermore, the use of Euler equations allows a reduction of computational time in the order of 50% compared to the Navier-Stokes modeling.     

适于系统仿真的冷却塔模型及其实验验证

从热力学、流体力学和传热传质的基本原理出发，以TRNSYS为仿真平台，建立了冷却塔动态数学模型，并对其进行了实验验证，结果表明辨识参数较准确时，仿真结果精度较高、可靠性较好，适合于系统仿真研究。     

适于系统仿真的表冷器模型及其实验验证

从热力学和传热传质的基本原理出发，以TRNSYS为仿真平台，建立了表冷器动态数学模型，并对其进行了实验验证，结果表明该模型仿真结果精度较高、可靠性较好，适合于系统仿真研究。     

岩土热物性集总热阻计量模型及其求解体系

由于地埋管周围岩土体状况的复杂性及由此导致的回归分析时统计性误差影响等原因,根据现有岩土热物性传热模型及热响应试验不能精确求解岩土热物性。探讨了消除解释变量性质影响的岩土集总热阻分析方法,并通过计量学误差分析体系进一步建立了岩土集总热阻计量模型,摆脱了相关不确定扰动的复杂影响,将这一传热问题转变为热工计量分析问题,根据逐时集总热阻即可计算出在各种进出口温度及初始土壤温度条件下的逐时单位管长换热量。以多个工程实测结果验证了该模型及其求解体系的有效性。     

A validation methodology aid for improving a thermal building model: case of diffuse radiation accounting in a tropical climate

As part of our efforts to complete the software CODYRUN validation, we chose as test building a block of flats constructed in Reunion island, which has a humid tropical climate. The sensitivity analysis allowed us to study the effects of both diffuse and direct solar radiation on our model of this building.With regard to the choice and location of sensors, this stage of the study also led us to measure the solar radiation falling on the windows. The comparison of measured and predicted radiation clearly showed that our predictions overestimated the incoming solar radiation, and we were able to trace the problem to the algorithm which calculates diffuse solar radiation. By calculating view factors between the windows and the associated shading devices, changes to the original program allowed us to improve the predictions, and so this article shows the importance of sensitivity analysis in this area of research.     

A ventilated slab thermal storage system model

A simplified dynamic thermal model of a hollow core concrete slab thermal storage system and associated room is described. The model is based on a thermal network that can address the heat exchange between the slab cores and the ventilation air, the thermal storage in the building fabric, and the effect of the heat disturbances on the room. The increase in convective heat transfer at the corners of the ventilation cores is also discussed. For normal cyclic operation, the simulated mass and zone temperatures are both in phase with measured performance data. The model root mean square error between the simulated and measured performance is no more than 0.5 °C for the average slab mass temperature and 1.0 °C for the zone air temperature.     

Experimental and simulation analysis of thermal behavior of large-span roof system under solar radiation

The large-span metal roof systems can produce a significant nonuniform temperature effect under solar radiation, leading to potential safety hazards. An experiment is conducted to study the nonuniform thermal behavior of a small-scale continuous welded stainless steel roof (CWSSR) system under solar radiation. The small-scale CWSSR system considered different roof slopes and sunward side and nightside. The efficiency of the numerical analysis of the thermal behavior of the roof slab is verified in comparison with the experimental results. Based on the numerical and experimental results, the thermal effect of a full-scale CWSSR system is studied under different orientations, wind speeds, and atmospheric temperature. Through the analysis of research results, the nonuniform thermal features of the CWSSR system are significant and cannot be overlooked. The temperature difference between the sunward side and nightside roof slab is positively correlated with the roof slope. The thermal behavior of the CWSSR system is greatly influenced by wind speeds but is less affected by orientations and atmospheric temperature.