Development of CFD-based multi-fidelity surrogate models for indoor environmental applications DOI Creative Commons
Nina Morozova

Опубликована: Июнь 20, 2022

This thesis presents a methodology for CFD-based multi-fidelity surrogate models indoor environmental applications. The main idea of this work is to develop model that has accuracy comparable CFD simulations but at considerably lower computational cost. It can perform real-time or faster than environments using ordinary office computers. be divided into three parts. In the first part, rigorous analysis feasibility affordable high-fidelity environment design and control carried out. chapter, we analyze two representative test cases, which imitate common airflow configurations, on wide range different turbulence discretization methods meet requirements cost, run-time, accuracy. We apply knowledge growth in power advances numerical algorithms order possibility performing accurate yet no-model LES with staggered discretizations studied show best performance. conclude computers are too slow used as primary tool control. Taking account laws computer prediction, estimate these applications next decades. second part dedicated developing data-driven predict comfort-related flow parameters ventilated room. chapter uses previously tested cavity heated floor case. developed predicts set parameters, such average Nusselt number hot wall, jet separation point, kinetic energy, enstrophy, temperature, were also comprehensively previous thesis. based gradient boosting regression, chosen due its performance among four machine learning methods. inputs temperature velocity values locations, act sensor readings. locations sensors determined by minimizing prediction error. does not require repetition applied since structure input data imitates Furthermore, low cost execution good makes it an effective alternative where rapid predictions complex configurations required, predictive third extension part. implement approach reduce training dataset generation. Gaussian process regression (GPR), capable handling data. variable fidelity constructed coarse- fine-grid model. approaches: GPR trained both high- low-fidelity without distinction, linear correction, co-cringing. approaches compared GPRs only All successfully generation while maintaining required level co-cringing demonstrates trade-off between Esta tesis presenta una metodología para modelos sustitutos de fidelidad múltiple basados en aplicaciones ambiente interior. La principal este trabajo es desarrollar un modelo que tenga precisión las simulaciones pero costo computacional considerablemente inferior. metodologia permite realizar tiempo real o más rápido utilizando ordinadores oficina ordinarios. Este se puede dividir tres partes principales. En la primera parte, lleva cabo análisis viabilidad asequibles alta el diseño y ambientes interiores. capítulo, analizamos dos casos, imitan configuraciones comunes flujo aire interior, amplia gama diferentes turbulencia métodos discretización. Aplicamos conocimiento sobre crecimiento potencia analizar posibilidad precisas Los sin con discretizaciones escalonadas muestran mejor rendimiento. Concluimos son demasiado lentas ser utilizadas como herramienta Teniendo cuenta leyes predicción del computacional, estimamos estas durante próximas décadas. segunda parte esta está dedicada al desarrollo sustituto basado datos predecir los parámetros habitación ventilada. El desarrollado predice conjunto flujo, número promedio pared caliente, punto separación chorro, energía cinética promedia, entrofia promedia temperatura promedia. basa regresión aumento gradiente, elegida debido su rendimiento preciso entre cuatro aprendizaje automático probados. Las entradas valores velocidad ubicaciones, actúan lecturas sensor. ubicaciones estos sensores determinaron minimizando error predicción. no requiere aplicación repetición ya estructura entrada imita Además, bajo ejecución buena lo convierten alternativa eficaz requieren predicciones rápidas complejas, predictivo modelo. tercera extensión parte. implementamos enfoque reducir generación entrenamiento. procesos gaussianos capaz manejar múltiple. construye CFD. Probamos enfoques múltiple: entrenado baja distinción, corrección lineal co-krigeaje. comparan solo fidelidad. Todos probados reducen éxito conjuntos comparación mientras mantienen nivel requerido precisión. co-krigeaje demuestra compensación

Optimal zoning for building zonal model of large-scale indoor space DOI
Bo Lan,

Zhun Yu,

Pei Zhou

и другие.

Building and Environment, Год журнала: 2022, Номер 225, С. 109669 - 109669

Опубликована: Окт. 6, 2022

Язык: Английский

Процитировано

9

A Visualized Method of Airflow between Adjacent Zones inside a Multizone Building Based on Pressure Difference Frequency: Airflow Mapping DOI Open Access

Jiajun Jing,

Dongseok Lee,

Jaewan Joe

и другие.

Indoor Air, Год журнала: 2023, Номер 2023, С. 1 - 19

Опубликована: Июль 3, 2023

The airflow movement inside a multizone building has significant impact on pollutant transfer, thermal comfort, and indoor air quality. However, there are difficulties in visualizing the with existing methods. This study proposes visualization method for evaluating airflows between adjacent internal zones based analysis of pressure difference frequency. After distribution absolute is measured wind pressures surfaces calculated, variation differences each couple analyzed three levels: greater than 0 Pa, equal to less Pa (for any given selected as target zones). Finally, an mapping created floor using visNetwork tool R language. A was applying proposed method. mappings were derived from detailed frequency zones, presenting variations direction dominant during measurement period visualized form. For example, 1F_Z2 1F_Z3 92.0%. spatial similarity directions can also be observed certain floors. results this experimental show that multiple easily identified without complex zone analysis. intuitively visualized, providing insight airtightness levels components. It rates computed provide more guidance control HVAC systems.

Язык: Английский

Процитировано

4

Development of Operating Strategies for Return Fan in HVAC System Considering Differential Pressure DOI Creative Commons
Hyein Lee, Hyo‐Jun Kim,

Jin-Hyun Lee

и другие.

Energies, Год журнала: 2024, Номер 17(21), С. 5289 - 5289

Опубликована: Окт. 24, 2024

The pressure difference in buildings causes indoor and outdoor airflow, significantly impacting the thermal environment building energy consumption due to introduction of air. is highly variable, influenced by wind speed, indoor–outdoor temperature differences, heating, ventilating air conditioning (HVAC) system operation, making it difficult consider this factor during general HVAC potentially leading an imbalance differences. Therefore, study proposes appropriate operation strategy for return fans considering proposed involves adjusting fan airflow maintain a constant balance, thereby controlling difference, satisfying environment, reducing consumption. To evaluate strategy, dynamic simulations using TRNSYS TRNFLOW were utilized, targeting one floor office equipped with variable volume (VAV) system. evaluation results showed that maximum decreased from −142 Pa −18 compared existing total was reduced 29%, highlighting importance differences operation.

Язык: Английский

Процитировано

1

Adjustment strategy for supply air volume balance and algorithm for multi-room differential pressure gradient in an air conditioning purifier system DOI
Jinsong Yang,

Lun Zhang,

Jiahui Liu

и другие.

Building and Environment, Год журнала: 2023, Номер 243, С. 110647 - 110647

Опубликована: Июль 28, 2023

Язык: Английский

Процитировано

2

Multivariable coupled prediction model for particulate matter concentration in the dynamic environment of a biologically clean room DOI Open Access

Han Meng,

Junjie Liu

Chinese Science Bulletin (Chinese Version), Год журнала: 2023, Номер 69(7), С. 866 - 877

Опубликована: Ноя. 15, 2023

To ensure the cleanliness of a biologically clean room, air change rate applied by an conditioning system is usually high, resulting in high energy consumption during its operation. One important reasons that law particle concentration for room not clear, and dynamic adjustment volume cannot be performed according to production load. In this study, biological with C-class environment was constructed simulate pharmaceutical plant. Under operating 10, 20, 30, 40 h−1, 36 groups particulate matter concentrations corresponding stationary, mild, severe activity types 13 people were tested frequency conversion system. A comparison test standard limit values shows when runs at h−1 ventilation times, value 0.5 μm 1/718 limit, indicating redundancy cleanliness. The has great energy-saving potential. observed 5 particles low volume. ratio 0.5 should used as criterion determining analysis experimental data provided number personnel, types, rate, rule concentration. proportional relationship between personnel growth rates under 10−40 given, offering more accurate reference design stage. Based on particles, light heavy-activity stationary type summarized group 1–3 people. Compared previous studies, which suggested 2–5 5–10 multiple type, respectively, study are practical significance. measured data, regression method adopted establish two multivariable coupled prediction models Model 1 model without any interactions variables, while 2 considers interaction variables. terms R2, higher degree fitting. 1, predict different conditions, closer real situation. Thus, required maintain can obtained using model, providing developing operation strategy such rooms.

Язык: Английский

Процитировано

2

Simulation Model for Pressure Difference Control to Prevent Cross-Infection in Hospitals Treating Normal and Epidemic Patients DOI

Yanbo Feng,

Han Zhu, Xiwen Feng

и другие.

Опубликована: Янв. 1, 2024

Download This Paper Open PDF in Browser Add to My Library Share: Permalink Using these links will ensure access this page indefinitely Copy URL DOI

Язык: Английский

Процитировано

0

Simulation model for pressure difference control to prevent cross-infection in hospitals treating normal and epidemic patients DOI
Yanbo Feng, Han Zhu, Xiwen Feng

и другие.

Energy and Buildings, Год журнала: 2024, Номер 319, С. 114529 - 114529

Опубликована: Июль 19, 2024

Язык: Английский

Процитировано

0

Field study on pressure differential mechanisms under static and dynamic disturbances in non-isobaric building zones DOI

Yufan Chang,

Zhengtao Ai, Jie Zong

и другие.

Energy and Buildings, Год журнала: 2024, Номер unknown, С. 115183 - 115183

Опубликована: Дек. 1, 2024

Язык: Английский

Процитировано

0

Application of virtual product design to the development of HVAC solution for Incheon International Airport Modular COVID-19 testing center DOI Creative Commons

Sun Jong Noh,

Mansu Park,

Sim Won Chin

и другие.

Case Studies in Chemical and Environmental Engineering, Год журнала: 2022, Номер 6, С. 100257 - 100257

Опубликована: Сен. 18, 2022

Owing to the spread of COVID-19, need for an inspection center that can quickly determine whether travelers using airport are infected has emerged. For rapid determination, not only polymerase chain reaction tests but also antigen-antibody and on-site analysis systems required. However, because it is time- cost-intensive construct a building meets standards negative pressure facilities, modular facilities being installed as alternatives. Existing have problems such increased energy consumption due outdoor air load condensation differences in indoor temperatures humidities caused by excessive external inflow achieve target change rate (ACH). In addition, owing installation additional devices, construction required use them other purposes future. To solve these problems, this study, recovery ventilation (ERV) was employed develop heating, conditioning (HVAC) solution Incheon International Airport COVID-19 Testing Center. shorten development period, virtual product design (VPD) computational fluid dynamics analysis-based experiments performed. application VPD, Modular Center completed 2 weeks. The measured all spaces applying optimal conditions derived through VPD. ERV, ACH airborne infectious isolation room exceeded value suggested international organizations.

Язык: Английский

Процитировано

2

Cleanrooms pressure cascade: standard PID-based solutions and step forward to MIMO control DOI
Branislav Jeremić, Aleksandar Rakić

Опубликована: Ноя. 9, 2022

This paper gives in-depth analysis of the cleanrooms pressure cascade problem, where starting point is state-of-the-art control practice for stabilization and disturbance rejection static air-flow rate. The plant components are modeled in order to obtain multivariable model a typical context heating-ventilation-air conditioning (HVAC) variable-air-volume (VAV) based control. Opposed standard solutions realized by independent PID loops, presented modelling enables proper effective high-performance plants with observed strong internal couplings. results problems arising from pharmaceutical factories Republic Serbia given case study, open issues highlighted.

Язык: Английский

Процитировано

0