Experimental and numerical studies on the thermal performance of ventilated BIPV curtain walls

2015 ◽  
Vol 26 (9) ◽  
pp. 1243-1256 ◽  
Author(s):  
Chi-ming Lai ◽  
Shuichi Hokoi
Keyword(s):  
Thermal Performance ◽  
Flow Mechanism ◽  
Pv System ◽  
Cfd Simulations ◽  
Buoyant Force ◽  
System A ◽  
Numerical Studies ◽  
Building Integrated Photovoltaic ◽  
Double Skin ◽  
Computational Fluid Dynamics Cfd

In this study, we integrated a photovoltaic (PV) system, a double-skin structure and a thermal flow mechanism to design ventilated building-integrated photovoltaic (BIPV) curtain walls that can autogenously control an environment using buoyant force. Full-scale experiments and computational fluid dynamics (CFD) simulations were conducted to investigate the flow pattern characteristics for the channel airflow and the thermal performance of the ventilated BIPV curtain walls under various heating conditions, wall thicknesses and types of openings. Channel flows for different channel widths under the same wall heating exhibited different flow patterns and therefore variations in thermal performance. The developed ventilated BIPV curtain walls effectively removed their solar heat gain while maintaining adequate wall thermal performance.

scholarly journals A Study on the Thermal Performance of Air-Type BIPVT Collectors Applied to Demonstration Building

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3120 ◽  
Author(s):  
Ji-Suk Yu ◽  
Jin-Hee Kim ◽  
Jun-Tae Kim
Keyword(s):  
Thermal Performance ◽  
Thermal Characteristics ◽  
Building Energy ◽  
Flow Path ◽  
Heating And Cooling ◽  
Building Integrated Photovoltaic ◽  
Opening Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Inlet Opening

Research on existing air-type PVT (photovoltaic/thermal) collectors has mainly focused on improving the efficiency of the collector itself and on using the energy produced by the collector in heating and cooling facilities and building energy. The first consideration in an air-type PVT system applied to a building facade is the collector arrangement and the flow path considering the collector performance. It is necessary to design the flow inside the air-type BIPVT (building integrated photovoltaic/thermal) collector so that it runs smoothly so as not to cause a dead space and a pressure drop inside the collector, which deteriorate the thermal performance. This study analyzed the thermal characteristics of an air-type BIPVT collector applied to a demonstration building (educational buildings) according to the air flow path and inlet opening ratio. For this purpose, the uniformity of the airflow in the collector was compared through the NX computational fluid dynamics (CFD) program, and the acquired thermal calories and thermal efficiency of the BIPVT collector were compared and analyzed. Based on the simulation results, the temperature and thermal characteristics of the BIPVT collector were compared.

Parametric Model of Dead Leg Steady-State Thermal Performance

2018 ◽  
Author(s):  
Arnaud Sanchis ◽  
Sonny Andersson ◽  
Atle Jensen
Keyword(s):  
Low Temperatures ◽  
Design Space ◽  
Production Systems ◽  
Parametric Model ◽  
Thermal Design ◽  
Piping System ◽  
Cfd Simulations ◽  
System A ◽  
Novel Approach ◽  
Computational Fluid Dynamics Cfd

During thermal design of Subsea Production Systems (SPS), Computational Fluid Dynamics (CFD) is used to calculate production fluid temperatures in dead legs of the system. One purpose of such simulations could be to calculate the amount of insulation needed to avoid low temperatures in the piping system. A novel approach to this type of analysis is presented here to build a parametric model able to map the dead leg performance against any set of input parameters. The workflow relies on a response surface analysis performed from the results of a limited set of CFD simulations run on a sparse simulation matrix that covers the design space. Once generated, the parametric model provides real-time results and may be used for screening, optimization or condition monitoring purposes.

Impact of Tile Design on the Thermal Performance of Open and Enclosed Aisles

2018 ◽  
Vol 140 (1) ◽  
Author(s):  
Sadegh Khalili ◽  
Mohammad I. Tradat ◽  
Kourosh Nemati ◽  
Mark Seymour ◽  
Bahgat Sammakia
Keyword(s):  
Thermal Performance ◽  
Inlet Temperature ◽  
Open Area ◽  
Cfd Simulations ◽  
Physical Separation ◽  
Hot Air ◽  
Airflow Distribution ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
Lower Noise

In raised floor data centers, tiles with high open area ratio or complex understructure are used to fulfill the demand of today's high-density computing. Using more open tiles reduces the pressure drop across the raised floor with the potential advantages of increased airflow and lower noise. However, it introduces the disadvantage of increased nonuniformity of airflow distribution. In addition, there are various tile designs available on the market with different opening shapes or understructures. Furthermore, a physical separation of cold and hot aisles (containment) has been introduced to minimize the mixing of cold and hot air. In this study, three types of floor tiles with different open area, opening geometry, and understructure are considered. Experimentally validated detail models of tiles were implemented in computational fluid dynamics (CFD) simulations to address the impact of tile design on the cooling of information technology (IT) equipment in both open and enclosed aisle configurations. Also, impacts of under-cabinet leakage on the IT equipment inlet temperature in the provisioned and under-provisioned scenarios are studied. In addition, a predictive equation for the critical under-provisioning point that can lead to a no-flow condition in IT equipment with weaker airflow systems is presented. Finally, the impact of tile design on thermal performance in a partially enclosed aisle with entrance doors is studied and discussed.

scholarly journals A Ducted Photovoltaic Façade Unit with Buoyancy Cooling: Part II CFD Simulation

Buildings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 133 ◽  
Author(s):  
Abdel Rahman Elbakheit
Keyword(s):  
Fluid Dynamics ◽  
Cfd Simulation ◽  
Operating Temperature ◽  
Incident Radiation ◽  
Pv System ◽  
Cfd Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Module Efficiency ◽  
Previous Experimental Study ◽  
Cooling Part

A ducted photovoltaic façade (DPV) unit was simulated using computational fluid dynamics (CFD). This is Part II of the study, which is a repetition of Part I—a previous experimental study of the ducted photovoltaic unit with buoyancy cooling. The aim of this study is to optimize the duct width behind the solar cells to allow for the cells to achieve maximum buoyancy-driven cooling during operation. Duct widths from 5 to 50 cm were simulated. A duct width of 40 cm allowed for the maximum calculated heat to be removed from the duct; however, the lowest cell-operating temperature was reported for a duct width of 50 cm. The results showed that the change in temperature (ΔT) between the ducts’ inlets and outlets ranged from 8.10 to 19.32 °C. The ducted system enhanced module efficiency by 12.69% by reducing the photovoltaic façade (PV) temperature by 27 °C from 100 to 73 °C, as opposed to the increased temperatures that have been reported when fixing the PV directly onto the building fabric. The maximum simulated heat recovered from the ducted PV system was 529 W. This was 47.98% of the incident radiation in the test. The total summation of heat recovered and the power enhanced by the ducted system was 61.67%. The nature of airflow inside the duct was explored and visualized by reference to the Grashof number (Gr) and CFD simulations, respectively.

scholarly journals Numerical Analysis of Flow across Brush Elements Based on a 2-D Staggered Tube Banks Model

Aerospace ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 19
Author(s):  
Xiaolei Song ◽  
Meihong Liu ◽  
Xiangping Hu ◽  
Xueliang Wang ◽  
Taohong Liao ◽  
...  
Keyword(s):  
Euler Number ◽  
Dynamic Pressure ◽  
Labyrinth Seals ◽  
System A ◽  
Brush Seal ◽  
Back Plate ◽  
Computational Fluid Dynamics Cfd ◽  
Secondary Air ◽  
Tube Banks ◽  
Gas Expansion

In order to improve efficiency in turbomachinery, brush seal replaces labyrinth seals widely in the secondary air system. A 2-d staggered tube bank model is adopted to simulate the gas states and the pressure character in brush seal, and computational fluid dynamics (CFD) is used to solve the model in this paper. According to the simulation results, the corrected formula of the Euler number and dimensionless pressure are given. The results show that gas expands when flow through the bristle pack, and the gas expansion closes to an isotherm process. The dynamic pressure increases with decreasing static pressure. The Euler number can reflect the seal performance of brush seals in leakage characteristics. Compared with increasing the number of rows, the reduction of the gap is a higher-efficiency method to increase the Euler number. The Euler number continually increases as the gap decreases. However, with the differential pressure increasing, Euler number first increases and then decreases as the number of rows increases. Finally, the pressure distribution on the surface of end rows is asymmetric, and it may increase the friction between the bristles and the back plate.

scholarly journals Influence of Artificial and Natural Cooling on Performance Parameters of a Solar PV System: A Case Study

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 29449-29457
Author(s):  
Subhash Chandra ◽  
Arvind Yadav ◽  
Mohd Abdul Rahim Khan ◽  
Mukesh Pushkarna ◽  
Mohit Bajaj ◽  
...  
Keyword(s):  
Performance Parameters ◽  
Solar Pv ◽  
Pv System ◽  
System A ◽  
Solar Pv System

scholarly journals Using CFD to Evaluate Natural Ventilation through a 3D Parametric Modeling Approach

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2197
Author(s):  
Nayara Rodrigues Marques Sakiyama ◽  
Jurgen Frick ◽  
Timea Bejat ◽  
Harald Garrecht
Keyword(s):  
Natural Ventilation ◽  
Parametric Modeling ◽  
Cfd Simulations ◽  
3D Design ◽  
Post Process ◽  
Test House ◽  
Model Set ◽  
Computational Fluid Dynamics Cfd ◽  
Set Up ◽  
Passive Strategy

Predicting building air change rates is a challenge for designers seeking to deal with natural ventilation, a more and more popular passive strategy. Among the methods available for this task, computational fluid dynamics (CFD) appears the most compelling, in ascending use. However, CFD simulations require a range of settings and skills that inhibit its wide application. With the primary goal of providing a pragmatic CFD application to promote wind-driven ventilation assessments at the design phase, this paper presents a study that investigates natural ventilation integrating 3D parametric modeling and CFD. From pre- to post-processing, the workflow addresses all simulation steps: geometry and weather definition, including incident wind directions, a model set up, control, results’ edition, and visualization. Both indoor air velocities and air change rates (ACH) were calculated within the procedure, which used a test house and air measurements as a reference. The study explores alternatives in the 3D design platform’s frame to display and compute ACH and parametrically generate surfaces where air velocities are computed. The paper also discusses the effectiveness of the reference building’s natural ventilation by analyzing the CFD outputs. The proposed approach assists the practical use of CFD by designers, providing detailed information about the numerical model, as well as enabling the means to generate the cases, visualize, and post-process the results.

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