18PA6B柴油机高低温水箱频繁液位报警问题分析及处理

针对18PA6B柴油机高低温水膨胀箱频繁出现液位低报警,导致运行人员频繁补水的问题,经过对可能的原因进行逐步排查,最终确认根本原因为高低温水回路存在集气现象,在整个高低温水系统高点增加排气阀后,故障排除。

防液击型高低温水冷冷凝机组的研发

目前现有的制冷机组在工作时经常会碰到压缩机出现液击的状况,原因是从蒸发器出来的氟利昂在还没有完全汽化的情况下被吸入压缩机,造成压缩机损坏,因为压缩机只能压缩气体而不能压缩液体,且易造成氟利昂泄露污染环境。因此,如何使氟利昂充分液化并减少制冷系统和环境受污染来保证润滑油性能不受影响、压缩机性能、制冷量、温升能保证标准范畴、压缩机使用寿命不受变化,是当前制冷行业发展亟待解决的技术难题。为此,浙江省农业机械研究院与浙江沃克制冷设备有限公司合作开发研制了防液击型高低温水冷冷凝机组,该机组将汽液分离器、回汽过滤器、干燥过滤器等制冷装置结合于一体,可有效防止压缩机液击现象的产生,使其装置高效节能,缩减设备占用体积,使设备和环境免受污染,安全可靠。

Influence of CaO-based expansive agent,superabsorbent polymers and curing temperature on pore structure evolution of early-age cement paste

Cracks easily generate in concrete at early age owing to the shrinkage deformation.CaO-based expansion agent(CEA)and superabsorbent polymers(SAP)have been extensively used for the mitigation of concrete shrinkage.The macroscopic properties of concrete are highly determined by the microstructure.In this study,the influence of CEA and SAP addition on the pore structure evolution of cement paste under different curing temperatures was evaluated via low-field nuclear magnetic resonance spectroscopy.Test results indicated that,in cement paste,a higher CEA content led to a higher porosity and a larger most probable pore diameter(MPPD).Meanwhile,SAP addition increased the porosity and MPPD of CEA cement paste at early age but decreased them after 7 d,and a higher SAP content always brought a higher porosity and MPPD.Furthermore,the addition of SAP led to a lower porosity and MPPD of CEA cement paste than that of plain cement paste after 14 d.Moreover,the porosity and MPPD of CEA cement paste decreased first and subsequently increased as the curing temperature raised.

抗剥落剂对沥青混合料耐久性的影响研究

选择典型胺类、非胺类抗剥落剂,以不同掺量对基质沥青进行改性得到混合料,对其进行老化试验,测得不同条件处理后的沥青混合料的残留稳定度、冻融劈裂强度比,以得到其最佳掺量的方法、及混合料路用性能的高低温水稳定性的特点。