噪声计算在职业病危害预评价中的应用

Application of noise calculation in pre-evaluation of occupational hazards

目的在职业病危害预评价中,更准确地预测噪声强度。方法以某发动机扩建工程噪声预测为例,介绍噪声计算在职业病危害预评价中的应用。结果噪声叠加计算公式为LP=10 lg[10Lp1/10+10Lp2/10],当作用于某一点的2个声源声压级相等,其合成的总声压级比1个声源的声压级增加3 dB。点声源衰减计算公式为ΔL=10 log(1/4πr2),不同距离衰减量可根据文中点声源随距离的声衰减曲线查找。结论原有厂房内添加噪声源后的噪声强度可以通过噪声叠加计算公式预测,离噪声源有一定距离的噪声强度可以通过噪声衰减计算公式预测。噪声计算方法简便,结果可靠。

[ Objective ] To more accurately predict noise intensity in pre-evaluation of occupational hazards. [ Methods ] Noise calcu- lation was introduced in the pre-evaluation of occupational hazard of application, with an engine noise prediction expansion project as an example. [ Results] Noise superposition computation formula was LP = 10 lg[ 10Lpl/I~ ＋ 10L^l~ ], as for a point with 2 sound pres- sure levels equal, the synthesis of total pressure level was increased by 3 dB, compared with the pressure level of 1 source. Point source attenuation formula wasAL = 10 log （ 1/4.rrr2 } , different distance attenuation quantity can be found according to the point source distance attenuation curve. [ Conclusion] The noise intensity in the original factory with noise source added can be forecasted via the noise superposition formula. The noise intensity with a certain distance from the noise source can be predicted through the noise attenuation calculation formula. Noise calculation method is simple, with reliable results.