单螺杆压缩机工作腔喷液过程几何特性及工作机理研究

Geometric Characteristic and Working Mechanism of Injection Process in Single Screw Compressor with Injection

为了分析工作腔喷液单螺杆压缩机喷液过程的几何特性及喷液机理,基于单螺杆压缩机的工作特性,确定了螺槽与喷液孔连通时的特征角度,在此基础上,建立了工作腔喷液的几何模型,得到了任意星轮转角位置处的有效喷液面积,分析了不同喷液孔初始位置及喷液孔径对有效喷液面积的影响。基于工作腔喷液的几何模型提出了喷液过程理论计算方法,对单螺杆压缩机工作腔喷液的机理进行了研究,结果表明:压缩机工作过程中,喷液孔面积随星轮转角呈现先增大后减小的趋势;喷液孔初始位置和喷液孔径两者共同影响喷液开始角度和喷液持续时间,喷液量受喷液面积和喷液孔前后压差这两个因素共同影响,且在喷液孔面积最大的起始位置存在一个最大单位角度喷液量。通过对工作腔喷液机理进行分析,可为以后单螺杆压缩机工作腔喷液过程的优化设计提供理论基础。

To analyze the working cavity injection mechanism and geometric characteristic of the injection process in single screw compressor （SSC）, the critical angles as the injection hole connecting with the screw groove are determined according to the working properties of SSC. Analyzing the critical angles, a geometry model of working cavity injection is established, and the effective injection area at a certain rotation angle of the star-wheel is evaluated. A influences of the initial position and the diameter of the injection hole on the effective injection area are discussed with this model. A theoretical calculating model of the injection process is also presented to reveal the working cavity injection mechanism in SSC. The analysis shows that the injection area increases firstly and then decreases with the star-wheel angle. The starting injection angle and the injection duration time are commonly affected by the initial position and diameter of injection hole, and the injection amount is affected by both the injection area and pressure difference before and after injection hole. There exists a biggest injection quantity per angle at the original position of the largest injection area.