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Motor Cooling
Published in Wei Tong, Mechanical Design and Manufacturing of Electric Motors, 2022
Cooling techniques are often divided into two categories: passive cooling and active cooling, depending on what the heat transfer mode would be or how cooling flows are generated. Passive cooling refers to cooling with no active mechanism such as fan or pump. Passive cooling techniques have been developed for a long time for motors that have low power losses. In a passive cooling mode, motor cooling primarily relies on heat conduction to transport the generated heat from the heat sources (e.g., stator winding) to the motor frame (e.g., motor housing and endbells) and then to dissipate the heat to the environment by natural convection and radiation. By eliminating fans or pumps, motor operation reliability is significantly increased. Compared with active cooling techniques, passive cooling techniques have lower costs, lower noise emission, and no power consumption. However, passive cooling techniques are restricted to low thermal load conditions. For large-size, heavy-duty motors, active cooling is the only choice.
Thermal Environment Design Strategies
Published in Chitrarekha Kabre, Synergistic Design of Sustainable Built Environments, 2020
The term ‘passive cooling’ generally denotes the dissipation of heat from buildings by the natural process of radiation, convection, and evaporation, which do not require the expenditure of any non-renewable energy. In many cases, evaporation and convection can be significantly enhanced by the use of motor-driven fans or pumps, which consume a small amount of electrical energy, and the word ‘hybrid’ has been adopted to characterize such processes (Yellott 1982).
Passive Cooling Systems
Published in Pablo La Roche, Carbon-Neutral Architectural Design, 2017
A passive cooling system is capable of transferring heat from a building to various natural heat sinks (Givoni, 1994). To achieve this, the building must have special design details, generally in some part of the envelope. Passive cooling systems provide cooling through the use of passive processes, which often use heat flow paths that do not exist in conventional or bioclimatic buildings.
Performance analysis of transparent BIPV/T double skin façades integrated with the decision-making algorithm for mixed-mode building ventilation
Published in Architectural Engineering and Design Management, 2023
Prapavee Karunyasopon, Dong Yoon Park, Duc Minh Le, Seongju Chang
Mixed-mode ventilation or hybrid ventilation in buildings utilizes a combination of natural ventilation and a mechanical system (HVAC). In automatic control systems, sensors, and window actuators, along with control algorithms, respond to outdoor and indoor space conditions in real-time. Natural ventilation provides passive cooling or passive heating by introducing fresh air to the cavity or an indoor space. However, there are weather constraints and environmental conditions that must be factored in when applying natural ventilation mode (Chen et al., 2018). Mechanical systems can be shifted to operate when natural ventilation mode is not sufficient or suitable. With its reduction of mechanical fan use, mixed-mode ventilation can create sustainable buildings, diminish energy demand, and save energy costs, while maintaining thermal comfort for occupants (Berkeley, 2018). Even though natural ventilation is a preferable operation mode, not all periods and climates are advantageous for this ventilation strategy. Therefore, the optimum control achieved by the mixed-mode ventilation strategy is needed to maintain an adequate level of indoor air quality and avoid building tendencies to overheat (CIBSE, 2005).
Computational investigations of battery thermal management system with environmental effects employing a combination of phase change materials and forced air cooling
Published in International Journal of Green Energy, 2022
R. Pradeep, T. Venugopal, R. Sivakumar
(Sabbah et al. 2008) Passive cooling utilizes natural conduction, convection, and radiation to cool a component. Active cooling requires the use of energy specifically dedicated to cooling the component. Active cooling systems are stronger than passive cooling systems in terms of reducing temperature. Passive cooling takes advantage of natural cooling, which takes longer to cool for a longerperiod of time but does not require much energy for its activity. Because of its efficiency in decreasing temperature in a limited amount of time, most individuals prefer the use of active cooling systems in hot or tropical climates over passive cooling. Compared to passive cooling, the problems of active cooling are primarily the financial costs and consumption of energy. It makes it much less energy efficient as well as less cost-effective because of the heavy energy demand of active cooling.
Effects of a liquid cooling vest on physiological and perceptual responses while wearing stab-resistant body armor in a hot environment
Published in International Journal of Occupational Safety and Ergonomics, 2022
Mengqi Yuan, Yuchen Wei, Qiqi An, Jie Yang
Stab-resistant body armor (SRBA) is widely used to protect personnel from operational hazards [1,2], and dramatically increases field survival rates and reduces the risk of mortality [3–5]. However, SRBA has a negative effect on the physiological [6–9] and perceptual [10,11] responses of the wearer, which may lead to heat stress and reduce movement and work performance. Cooling systems are one of the most feasible approaches to reduce heat stress and improve the thermal comfort and working efficiency of personnel in military, aerospace, firefighting and industrial environments (e.g., mining, iron, glass and rubber foundries) [12,13]. Cooling systems can be either passive cooling systems (e.g., phase change material) or active cooling systems (e.g., liquid cooling and forced air ventilation).