A set of compressed natural gas (CNG) multi-point direct injection system of spark-ignited engines and the corresponding measurement and data acquisition systems were developed in this paper. Based on different inject...A set of compressed natural gas (CNG) multi-point direct injection system of spark-ignited engines and the corresponding measurement and data acquisition systems were developed in this paper. Based on different injection modes, the mixture formation and combustion of CNG low-pressure direct injection (LPDI) engines were studied under varying factors such as air/ fuel ratio, injection timing. Meanwhile, three-dimensional simulations were adopted to explain the mixture formation mechanisms of CNG low-pressure compound direct injection (LPCDI) mode. On the basis of test results and simulation of the mixture homogeneous degree, the conception of injection window was proposed, and the LPCDI mode was proved to be more beneficial to the mixture concentration stratification formation in cylinder under lean-burning conditions, which resulted in effective combustion and stability.展开更多
A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of...A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of gradient elution curves.The experimental results verified the theoretical analyses of the applied method.This self-designed control system can achieve approving accuracy,repeatability and low cost,which has a bright outlook for domestic applications.展开更多
基金Supported by National High Technology Research and Development Program ("863" Program) of China (No.2008AA11A114)
文摘A set of compressed natural gas (CNG) multi-point direct injection system of spark-ignited engines and the corresponding measurement and data acquisition systems were developed in this paper. Based on different injection modes, the mixture formation and combustion of CNG low-pressure direct injection (LPDI) engines were studied under varying factors such as air/ fuel ratio, injection timing. Meanwhile, three-dimensional simulations were adopted to explain the mixture formation mechanisms of CNG low-pressure compound direct injection (LPCDI) mode. On the basis of test results and simulation of the mixture homogeneous degree, the conception of injection window was proposed, and the LPCDI mode was proved to be more beneficial to the mixture concentration stratification formation in cylinder under lean-burning conditions, which resulted in effective combustion and stability.
基金the National High Technology Research and Development Program (863) of China(No. 2009AA04Z326)the National Natural Science Foundation of China (Nos. 60671059, 60871091 and60588101)+1 种基金the National Basic Research Program (973) of China (Nos. 2005CB724302 and 2005CB724303)the 111 Project from the Ministry of Education of China(No. B08020)
文摘A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of gradient elution curves.The experimental results verified the theoretical analyses of the applied method.This self-designed control system can achieve approving accuracy,repeatability and low cost,which has a bright outlook for domestic applications.
