Development of a 100 MPa water–gas two-phase fluid pressurization device

This paper introduces a 100 MPa water gas twophase fluid pressurization device.The device can provide 100 MPa gas pressure and 200 MPa liquid pressure for small volume(<20 mL)high-pressure experimental devices.This device can make the pressure control independent of the temperature control without changing the material components of the system.The resolution of this device in adjusting the pressure is±0.2 MPa in the process of boosting and depressurizing.This pressure boosting device generates very little vibration during work and it can be used in experiments with strict requirements on vibration.As a thermodynamic parameter,pressure has a great influence on matter.In the field of experimental geochemistry,pressure is not only an experimental method and an extreme condition but an important physical parameter independent of temperature and chemical composition.

Influence of confi ning pressure and impact loading on mechanical properties of amphibolite and sericite-quartz schist

In order to investigate the dynamic mechanical properties of amphibolite and sericite-quartz schist under confi ning pressure, two rocks are subjected to impact loadings with different strain rates and confi ning pressures by using split Hopkinson pressure bar equipment with a confi ning pressure device. Based on the experimental results, the stress-strain curves are analyzed and the effects of confi ning pressure and strain rates on the dynamic compressive strength, peak strain and failure mode are summarized. The results show that:(1) The characteristics of two rocks in the ascent stage of the stressstrain curve are basically the same, but in the descent stage, the rocks gradually show plastic deformation characteristics as the confi ning pressure increases.(2) The dynamic compressive strength and peak strain of two rocks increase as the strain rate increases and the confi ning pressure effects are obvious.(3) Due to the effect of confi ning pressure, the normal stress on the damage surface of the rock increases correspondingly, the bearing capacity of the crack friction exceeds the material cohesion and the slippage of the fractured rock is controlled, which all lead to the compression and shear failure mode of rock. The theoretical analysis and experimental methods to study the dynamic failure mode and other related characteristics of rock are useful in developing standards for engineering practice.

Analysis and verification of gas content and pressure change rate characteristics in hydraulic system

Gas content of the hydraulic system directly affects the rate of pressure change of the hydraulic system. The purpose of this paper is to establish a mathematical model of oil gas content, hydraulic system pressure and pressure rise rate, obtain corresponding oil pressure value when the pressure rise rate of different gas content is maximum, and verify the accuracy of this conclusion by the FLUENT simulation software. On this basis, a rapid pressure building device of the hydraulic system is developed and designed. The above oil pressure value is used as the working cut-off pressure of the rapid pressure building device, and then the hydraulic oil pump continues to pressurize to the highest working pressure required by the system. The research content can replace the hydraulic system from the initial low pressure to the rapid pressure build-up of the oil, thus increasing the construction pressure of the hydraulic system. The research results show that the rapid pressure building device effectively reduces the time for the hydraulic system to establish pressure. Through the analysis of theoretical derivation and the collected experimental data, the error is about 5.9%, which verifies the correctness of the theoretical formula.