【摘要】 针对线性压缩机随工况和热负荷变化而引起共振频率和活塞中心位置偏移量改变的问题,建立了关于压缩机共振频率的线性等效模型和傅里叶变换计算模型。两种模型用来预测线性压缩机的共振频率,后者同时用来计算活塞中心位置偏移量,模型中考虑了不同行程、不同排气压力对共振频率的影响以及不同行程、不同排气压力和不同运行频率对活塞中心位置偏移量的影响。为了验证模型的有效性,搭建了用来测量线性压缩机共振频率和活塞中心位置偏移量的测试系统,并将测量结果与模型所计算结果进行对比,结果表明,线性等效模型相比于傅里叶变换计算模型能更加准确的预测线性压缩机的共振频率;线性压缩机的共振频率随着行程的增加而逐渐减小,随着排气压力的增加而逐渐增加。实验表明,线性压缩机活塞中心位置偏移量随行程的增加而几乎不变,随着排气压力的增加而逐渐增加。傅里叶变换计算模型针对不同行程下活塞中心位置偏移量预测值高于实际值;但在不同排气压力或不同行程下的活塞偏移量可用该模型计算压缩机在上止点位置的偏移量来进行预测,误差不大于10%。更多还原

【Abstract】 Here, aiming at the problem of resonance frequency and piston offset’ variation caused by working conditions and heat load’ change in linear compressor, linear equivalent model and Fourier transformation calculation one of linear compressor resonance frequency were established. Both of them were used to predict resonance frequency of linear compressor and the latter was also used to predict piston central position offset. Effects of stroke and discharge pressure on resonance frequency were considered in models, and effects of stroke, discharge pressure and operating frequency on piston offset were also considered in models. To verify the effectiveness of models, a testing system was constructed to measure resonance frequency and piston offset of linear compressor. The test results were compared with the calculated ones. Results showed that compared with Fourier transformation calculation model, the linear equivalent model can predict resonance frequency more accurately; resonance frequency gradually decreases with increase in stroke and increases with increase in discharge pressure. Tests showed that piston offset of linear compressor is almost a constant with increase in stroke and gradually increases with increase in discharge pressure; piston offset values predicted with Fourier transformation calculation model under different strokes are higher than the actual test ones, but piston offsets under different strokes and discharge pressures can be predicted by using this model to calculate the compressor’s offsets at the position of top dead center(TDC), the error is less than 10%.更多还原