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利用计算流体力学技术并结合现场实测分析分层空调系统设计关键参数如送风量、送风速度及分层高度等对某高大焊接厂房室内双扩散对流及通风空调效果和效率的影响。同时,还分析高大焊接厂房分层通风空调系统的适用性。研究结果表明:厂房下部风口排风比宜取为75%;送风量安全系数Ks可取为2.5~4.0;提高送风速度、下部排风口底部安装高度及降低分层高度均无法有效提升厂房通风空调效果和效率;各工况下厂房室内流体运动、热、质输运为双扩散混合或自然对流,焊接表面Nusselt数及Sherwood数基本不变;当厂房焊接烟尘散发量大时,分层空调节能性是一大挑战。将焊接热和污染源简化为稳态散发的条缝形热和污染面源,室内焊接烟尘质量浓度模拟值与实测值较好地吻合,相对误差为11.2%。
The effects of key parameters of stratified air-conditioning system design, such as blast volume, blast velocity and stratification height, on the effect and efficiency of dual diffusive convection and ventilation and air conditioning in a high-intensity welding plant were analyzed by using computational fluid dynamics and field measurements. At the same time, also analyzes the applicability of the high-density welding plant stratified ventilation and air conditioning system. The results show that the outlet air ratio at the lower part of the plant should be 75% and the safety coefficient Ks at the air supply should be 2.5-4.0. The improvement of the air supply speed, the installation height of the bottom exhaust outlet and the height of the delamination can not effectively enhance the plant Ventilation and air conditioning effect and efficiency; Indoor fluid movement, heat and mass transport in the workshop under various conditions are double diffusion mixing or natural convection, Nusselt number and Sherwood number of the welding surface are basically unchanged; when the welding fumes emitted by the plant are large, Air conditioning energy saving is a big challenge. The welding heat and pollution sources were reduced to the steady-state strip-shaped heat and pollution surface source. The simulated indoor welding soot mass concentration was in good agreement with the measured value, with a relative error of 11.2%.