Nonlinear dynamic analysis of solution multiplicity of buoyancy ventilation in a typical underground structure
- Chongqing Univ. (China); Chongqing Univ. (China). Key Lab. of New Technology for Construction of Cities in Mountain Area
- Chongqing Univ. (China); Chongqing Univ. (China). National Center for International Research of Low-carbon and Green Buildings
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
Buoyancy ventilation is widely used in underground buildings, such as underground hydropower stations. Multiple solutions of buoyancy ventilation may exist in those underground structures. In this study, we developed a transient model comprising an ordinary differential equation system to describe buoyancy ventilation patterns in typical two-zone underground structures. Additionally, the accuracy of the model was validated. Nonlinear dynamical analysis was conducted to study multiple steady-state airflow. According to mathematical derivation, the configuration of one local heat source at the bottom corner introduces two stable solutions. The criterion to determine the stability and existence of solutions for more general scenarios was developed. Using this criterion, we obtained the multiple steady states of any two-zone underground buildings for different stack height ratios and the strength ratios of the heat sources. Furthermore, this criterion can be adopted for the design of buoyancy ventilation or natural smoke ventilation systems. Designers can change the height ratio of the stack or the heat ratio of two zones to induce the desired ventilation patterns. Finally, a case study was conducted with field measurements to demonstrate the use of the nonlinear dynamical analysis method to investigate the multiple steady states of buoyancy ventilation. Through the case study, we validated that the proposed criterion could produce the same result as the nonlinear dynamical analysis.
- Research Organization:
- National Renewable Energy Laboratory (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE); National Natural Science Foundation of China (NNSFC); National Key R&D Program of China
- Grant/Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1660080
- Report Number(s):
- NREL/JA-5500-77333; MainId:26279; UUID:be744160-90a2-4403-8b9a-02c362cb23d7; MainAdminID:14060
- Journal Information:
- Building and Environment, Journal Name: Building and Environment Vol. 171; ISSN 0360-1323
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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