In the gas pipeline system, safe operation of a gas regulator determines the stability of the fuel gas supply, and the medium-low pressure gas regulator of the safety precaution system is not perfect at the present st...In the gas pipeline system, safe operation of a gas regulator determines the stability of the fuel gas supply, and the medium-low pressure gas regulator of the safety precaution system is not perfect at the present stage in the Bei- jing Gas Cxroup; therefore, safety precaution technique optimization has important social and economic signific- ance, In this paper, according to the running status of the medium-low pressure gas regulator in the SCADA sys- tem, a new method for gas regulator safety precaution based on the support vector machine （SVM） is presented. This method takes the gas regulator outlet pressure data as input variables of the SVM model, the fault categories and degree as output variables, which will effectively enhance the precaution accuracy as well as save significant manpower and material resources.展开更多
In view of some of the characteristics of a high-medium pressure gas regulator, such as small fault samples, many fault types and complex fault features etc, in order to improve the accuracy of fault precaution in thi...In view of some of the characteristics of a high-medium pressure gas regulator, such as small fault samples, many fault types and complex fault features etc, in order to improve the accuracy of fault precaution in this paper, a fault diagnosis method based on the combination of the improved wavelet packet and pressure harmonic distortion rate is proposed. On the basis of the harmonic distortion rate of the outlet pressure and the energy value of each frequency band obtained by improved wavelet packet decomposition, the rules for fault data were summarized. Finally, a safety precaution model of the high-medium pressure gas regulator is established.展开更多
In China, Pinus pumila is mainly distributed in Daxing’anling, while those growing in the eastern Daxing’anling are primarily covered under the jurisdiction of Huzhong Forest Bureau. P. pumila is an evergreen shrub,...In China, Pinus pumila is mainly distributed in Daxing’anling, while those growing in the eastern Daxing’anling are primarily covered under the jurisdiction of Huzhong Forest Bureau. P. pumila is an evergreen shrub, 3-6 m high, and always grows vigorously. Its trunks creep along the ground, usually 10 m long or more. It is easily flammable because of the large amounts of resins and volatile oils in its body. Attacking forest fires is a dangerous work, especially in P. pumila scrubs. The fires in P. pumila scrubs are very different from those in other forest types, e.g. fierce combustion and heavy smoke. In this paper, the distribution characteristics of P. pumila scrubs were presented. Attacking techniques and safety precautions for attacking fires in P. pumila scrubs were also discussed.展开更多
基金supported by Science and technology project of Beijing from Beijing Municipal Science&Technology Commission
文摘In the gas pipeline system, safe operation of a gas regulator determines the stability of the fuel gas supply, and the medium-low pressure gas regulator of the safety precaution system is not perfect at the present stage in the Bei- jing Gas Cxroup; therefore, safety precaution technique optimization has important social and economic signific- ance, In this paper, according to the running status of the medium-low pressure gas regulator in the SCADA sys- tem, a new method for gas regulator safety precaution based on the support vector machine （SVM） is presented. This method takes the gas regulator outlet pressure data as input variables of the SVM model, the fault categories and degree as output variables, which will effectively enhance the precaution accuracy as well as save significant manpower and material resources.
基金supported by Science and technology project of Beijing in 2015 from Beijing Municipal Science&Technology Commission
文摘In view of some of the characteristics of a high-medium pressure gas regulator, such as small fault samples, many fault types and complex fault features etc, in order to improve the accuracy of fault precaution in this paper, a fault diagnosis method based on the combination of the improved wavelet packet and pressure harmonic distortion rate is proposed. On the basis of the harmonic distortion rate of the outlet pressure and the energy value of each frequency band obtained by improved wavelet packet decomposition, the rules for fault data were summarized. Finally, a safety precaution model of the high-medium pressure gas regulator is established.
基金supported by the Central Public-interest Scientific Institution Basal Research Fund Supporting Program(CAFRIFEEP200809)the State Forestry Administration Key Project (2006-84)
文摘In China, Pinus pumila is mainly distributed in Daxing’anling, while those growing in the eastern Daxing’anling are primarily covered under the jurisdiction of Huzhong Forest Bureau. P. pumila is an evergreen shrub, 3-6 m high, and always grows vigorously. Its trunks creep along the ground, usually 10 m long or more. It is easily flammable because of the large amounts of resins and volatile oils in its body. Attacking forest fires is a dangerous work, especially in P. pumila scrubs. The fires in P. pumila scrubs are very different from those in other forest types, e.g. fierce combustion and heavy smoke. In this paper, the distribution characteristics of P. pumila scrubs were presented. Attacking techniques and safety precautions for attacking fires in P. pumila scrubs were also discussed.
