Papers by Keyword: Air-Cooled

Abstract: This paper presents the design and development of a 30-kW 3D printed based air-cooled silicon carbide (SiC) inverter for electric vehicle application. Specifically, an all-SiC air-cooled power module is designed, aiming at reduced thermal resistance for high temperature and high power density operation. The module assembly incorporates three major parts: an optimized 3D printed heat sink, a SiC MOSFET phase leg module, and a two-channel gate driver. The electrical and thermal performance of the power module is evaluated through double pulse test and continuous operation. Based on the air-cooled power module, a three-phase half-bridge voltage source inverter with 3D-printed air duct is built and tested to further verify the performance of the power module.

Abstract: In this research work, the effect of cooling rate on fatigue behaviour of eutectic A413 Al-Si cast alloy is investigated. Castings produced by two different cooling rates, water-cooled and air-cooled are studied. The structural morphology of alloy castings was characterized using Inverted Trinocular Metallurgical Optical Microscopy. A Comprehensive tension–tension fatigue test was carried out with a stress ratio of R=0.5, and a sinusoidal waveform under three different mean stress conditions (25%, 50% & 75% of UTS) at room temperature (32°C). The microstructural evaluations show that the eutectic script size is smaller for water-cooled casting than the air-cooled casting. It is also observed that the fatigue life of the water-cooled cast alloy is greater than that of cast alloy produced with conventional air-cooled method.

Abstract: For a medium air-cooled asynchronous motor, the physical model of cooling air inside the motor was established to research the air flow distribution and characteristics of the internal flow of the medium motor. By the finite volume method according to the computational fluid mechanics (CFD) principle, the three-dimensional turbulent flow field in computational domain was simulated numerically using boundary conditions of the pressure inlet and outlet obtained from engineering calculations. From the result, the thermal field of stator and rotor was calculation. The results show that the wind speed of cooling air duct which near the both ends was higher than the middle. It causes the temperature of the motor which near the both ends was lower than the middle part. The maximum temperature rise of the motor appear in the middle of the upper windings, and the specific value was 74K.

Abstract: Many power plants adopt air-cooled condensers (ACC) with finned tubes, using ambient air to condense turbine exhaust steam. Each condenser unit is mainly composed of two heat transfer surfaces like A and large diameter axial flow fans driving air. In the study of environmental wind effects, etc, due to the condenser unit size is bigger, it is necessary to simplify the condenser unit internal flow and heat transfer calculation, but the deviations introduced by these simplifies failed to get enough attention. In view of one condenser unit, three kinds of flow and heat tansfer combinated model were respectively investigated. A computational fluid dynamics software (CFD) is used to solve the problem.Research priority is analyzing the deviations of internal flow and heat transfer features in the condenser unit according to the extracted datum. The study gives some useful informatin to the design of a thermal power plant with an ACC system.

Abstract: In the study, LiBr absorption refrigeration machine runs in the air-cooled condition, combined with temperature and humidity independent control and the air condition end with radiant cooling, improving the system operation mode. Calculation and simulation were carried out to study the performance of the system, and effects of the cooling air inlet temperature and flow rate, refrigerant water outlet temperature on system performance, which will have the important theoretical significance for the development and application of the minitype solar lithium bromide unit.

Abstract: The mechanical properties and microstructure of Mn-series bainitic steel as 5Mn2SiNbTi after air cooling and tempering have been investigated in this paper. The results show that the investigated steel show high strength (tensile strength up to 671MPa), low toughness (20J at -30°C) after hot rolling (final rolling at 1050°C) and air cooling. Medium temperature tempering can improve the toughness, without sacrificing strength of the steel. After tempering at 450°C for 1h, the steel obtained 632MPa tensile strength, 467MPa yield strength, 140J impact energy at -30°C, remaining 25.0% elongation. It is indicated that the tested steel can gain excellent combination of strength and toughness without precious alloy adding, control rolling and control cooling.

Abstract: Experimental research on resistance and heat transfer properties of corrugated plate air-cooled heat exchanger under the condition of variable air and hot water flow rates has been conducted. The pressure drop and convection heat transfer coefficient correlation expressions both the air side and hot water side are acquired, where the Reynolds number for air side ranges from 401 to 6602 and the Reynolds number for water side ranges from 2536 to 19301 are adaptable.

Abstract: This study presents heat transfer rate and temperature distributions for the prediction of each component in an air-cooled motorcycle engines. The 3-D finite element method was used to solve the temperature field and heat transfer rate for each component (intake valves, exhaust valves, piston, piston rings, cylinder head and cylinder) of motorcycle engine when the piston is in TDC and BDC. The results shows that the fractions of heat transfer rate for each component are as follows: intake valves 11％, exhaust valves 8％, cylinder head 21％, the piston 35％ and the cylinder 25％. And the temperature measurement value is in good agreement with experimental data within 20%.