Condition Monitoring of IGBT Module and Forced Air Cooling System Using Time Constants of Heat Sink Temperature Cooling Curve

Author(s):  
Jun Zhang ◽  
Xiong Du ◽  
Shuai Zheng
2021 ◽  
Vol 09 (03) ◽  
pp. E482-E486
Author(s):  
Stanislas Chaussade ◽  
Einas Abou Ali ◽  
Rachel Hallit ◽  
Arthur Belle ◽  
Maximilien Barret ◽  
...  

Abstract Background and study aims The role that air circulation through a gastrointestinal endoscopy system plays in airborne transmission of microorganisms has never been investigated. The aim of this study was to explore the potential risk of transmission and potential improvements in the system. Methods We investigated and described air circulation into gastrointestinal endoscopes from Fujifilm, Olympus, and Pentax. Results The light source box contains a lamp, either Xenon or LED. The temperature of the light is high and is regulated by a forced-air cooling system to maintain a stable temperature in the middle of the box. The air used by the forced-air cooling system is sucked from the closed environment of the patient through an aeration port, located close to the light source and evacuated out of the box by one or two ventilators. No filter exists to avoid dispersion of particles outside the processor box. The light source box also contains an insufflation air pump. The air is sucked from the light source box through one or two holes in the air pump and pushed from the air pump into the air pipe of the endoscope through a plastic tube. Because the air pump does not have a dedicated HEPA filter, transmission of microorganisms cannot be excluded. Conclusions Changes are necessary to prevent airborne transmission. Exclusive use of an external CO2 pump and wrapping the endoscope platform with a plastic film will limit scatter of microorganisms. In the era of pandemic virus with airborne transmission, improvements in gastrointestinal ventilation systems are necessary to avoid contamination of patients and health care workers.


Author(s):  
Doyoung Shin ◽  
Gwang Hyeok Seo ◽  
Min Wook Na ◽  
Sung Joong Kim ◽  
Yonghee Kim ◽  
...  

Nowadays Small Modular Reactors (SMRs) have been receiving considerable attentions worldwide for potential advantages of an excellent flexibility for siting, low capital investment, and advanced safety. In Korea, a new research project has launched for the development of a conceptual design of a further advanced SMR which aims for a naturally-safe and autonomous operation, so called Autonomous Transportable On-demand reactor Module (ATOM). Major design objectives of the ATOM system are focused on the soluble boron-free (SBF) primary coolant system which enables the SMR to operate automatically in a load following mode. For the secondary system, the SCO2 power conversion cycle with air-cooling system as a final heat sink is being considered. The air-cooling system is expected to show flexible response even to extreme environmental conditions, such as a desert where utilization of cooling water is limited. The objective of this study is a feasibility assessment for applying the air-cooling system as a final heat sink of the ATOM by means of experimental work. As a 1st phase of the ATOM development, we first conducted the experiments using a typically considered primary coolant, water-steam, to verify that air flow has enough cooling capability to remove developed heat which the coolant carries. An Integrated Condensation Loop with Air-cooling System (ICLASS) experimental facility with three pressure boundaries (Steam, coolant, and air) was established. The cooling capability of the air-cooling system was evaluated by varying steam mass flow rate, coolant flow rate, and air environment temperature as experiment variables. Overall heat transfer rate by condensation was compared with numerical simulations of a 1D thermal-hydraulics analysis code, using the MARS model of the ICLASS facility.


Author(s):  
Hiroyuki Yamazaki ◽  
Yoshiaki Nishimura ◽  
Masahiro Abe ◽  
Kazumasa Takata ◽  
Satoshi Hada ◽  
...  

Tohoku Electric Power Company, Inc. (Tohoku-EPCO) has been adopting cutting-edge gas turbines for gas turbine combined cycle (GTCC) power plants to contribute for reduction of energy consumption, and making a continuous effort to study the next generation gas turbines to further improve GTCC power plants efficiency and flexibility. Tohoku-EPCO and Mitsubishi Hitachi Power Systems, Ltd (MHPS) developed “forced air cooling system” as a brand-new combustor cooling system for the next generation GTCC system in a collaborative project. The forced air cooling system can be applied to gas turbines with a turbine inlet temperature (TIT) of 1600deg.C or more by controlling the cooling air temperature and the amount of cooling air. Recently, the forced air cooling system verification test has been completed successfully at a demonstration power plant located within MHPS Takasago Works (T-point). Since the forced air cooling system has been verified, the 1650deg.C class next generation GTCC power plant with the forced air cooling system is now being developed. Final confirmation test of 1650deg.C class next generation GTCC system will be carried out in 2020.


Author(s):  
Kazuaki Yazawa ◽  
Gary L. Solbrekken ◽  
Avram Bar-Cohen

A compact, energy efficient heat sink design methodology is presented for shrouded, parallel plate fins in laminar flow. The analytic model accounts for the sensible temperature rise of the air flowing between fins, convective heat transfer to the flowing stream, and conduction in the fins. To evaluate the efficiency of the air cooling system, consideration is also given to the determination of the fan pumping power. This paper focuses on the optimization of the heat sink-fan combination for energy efficiency, subject to volumetric constraints. The design optimum is found by matching the most efficient operating point of the fan with the corresponding optimum fin geometry. A series of parametric studies was completed to identify the sensitivity of the cooling solution to parametric variations. This numerically validated model has been used to visualize the parametric impact of dealing with “real world” manufacturing limitation in the development of thermal packaging solutions for notebook computers and other electronic products.


2018 ◽  
Vol 12 (4) ◽  
pp. 4117-4126
Author(s):  
P. Rakkwamsuk ◽  
P. Paromupatham ◽  
K. Sathapornprasath ◽  
C. Lertsatitthanakorn ◽  
S. Soponronnarit

A thermoelectric (TE) air-cooling system for dehumidifying indoor air in a building was investigated. The system was composed of 4 TE modules. The cold sides of the TE modules were fixed to an aluminum heat sink to remove moisture in the air of a test chamber of 1 m3 volume, while a heat sink with circulating cooling water at the hot sides of the TE modules was used for heat release. The effects of input electric current to the TE modules and air flow rate through the heat sink were experimentally determined. The system’s performance was evaluated using dehumidification effectiveness and coefficient of performance (COP). A suitable condition occurred at 18.5 A of current flow and 240 W of power being supplied to the TE modules with a corresponding cooling capacity of 149.5 W, which gave a dehumidification effectiveness of 0.62. Therefore, it is anticipated the proposed TE dehumidifier concept will contribute to the air conditioning system’s reduction of room humidity. 


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