In this paper,the piston type valve core and the unbalanced moment on its bottom are studied.To decrease the influence of non-common geometrical factors,a simplified model of the piston type globe valve is proposed in...In this paper,the piston type valve core and the unbalanced moment on its bottom are studied.To decrease the influence of non-common geometrical factors,a simplified model of the piston type globe valve is proposed in this study.Based on the computational fluid dynamics(CFD)method,the effects of different geometrical parameters on the unbalanced moment existing on the bottom of the valve core,which include the bending radius of the inlet flow channel,the diameter of the special-shaped pipe,and the height of the valve core,are studied.Finally,the effects of geometrical parameters on the unbalanced moment on the bottom of the valve core are clarified by correction and variation classification and provide a basis for further optimizing the structure of the piston type valve.The results show that the unbalanced moment decreases with the increase of the bending radius of the inlet flow channel,but increases with the increase of the diameter of the special-shaped pipe and the height of the valve core.Moreover,the relation between the unbalanced moment and flow rate is proposed.展开更多
External contamination particles or wear particles corroded by a valve body are mixed into the fluid. As a result, when the fluid enters the fitting clearance of the valve core, it can cause an increase in resistance ...External contamination particles or wear particles corroded by a valve body are mixed into the fluid. As a result, when the fluid enters the fitting clearance of the valve core, it can cause an increase in resistance and lead to sticking failure of the valve core. This paper analyzes solid-liquid flow characteristics in fitting clearances and valve-core sticking based on the Euler-Euler model, using a typical hydraulic valve as an example. The impact of particle concentration and diameter on flow characteristics and valve-core sticking force was analyzed. The highest volume fraction of particles was in the pressureequalizing groove(PEG), with peak values increasing as the particle diameter increased. The sticking force increased with increasing particle concentration. When the particle diameter was 12 μm, the sticking force was the largest, making this the sensitive particle diameter. Particle distribution and valve-core sticking force were compared for oval, rectangular, and triangular PEGs. The fluid-deflection angles in oval and rectangular PEGs were larger, and their values were 32.83° and 39.15°, respectively. The fluid-deflection angle in the triangular PEG was relatively small, less than 50% that of the oval or rectangular PEGs. The particle-volume-fraction peaks in oval, rectangular, and triangular PEGs were 0.0317, 0.0316, and 0.0312, respectively. The sticking forces of oval, rectangular, and triangular PEGs were 4.796, 4.802, and 4.757 N, respectively when the particle diameter was 12 μm. This work provides a reference for design and research aimed at reducing valve-core sticking.展开更多
A YDC type hydraulic hammer is a new valve-type double action hydraulic hammer suitable for oil and gas well drilling.It is hard to find out the optimal matching relationship among various factors based on experience ...A YDC type hydraulic hammer is a new valve-type double action hydraulic hammer suitable for oil and gas well drilling.It is hard to find out the optimal matching relationship among various factors based on experience and experiments,for the matching relationships of inner pressure is complex and the impact performance is influenced by many factors.In this paper,the operating principle of a YDC type hydraulic hammer was investigated,the force applied to the main moving components(valve core and hammer)was analyzed and a dynamic model of valve core and hammer in each operating stage was established.Then,a hydraulic hammer performance optimization design software was developed on the Matlab software platform,and the performance parameters calculated by the software were compared with the laboratory test results.The following research results were obtained.Firstly,single impact energy,impact frequency and impact power increase with the increase of pump displacement or the decrease of flow bean diameter,and they increase firstly and then decrease with the increase of area difference between the upper and lower chambers.Secondly,with the increase of hammer weight,single impact energy and impact power increase,but the impact frequency decreases slowly.Thirdly,with the increase of hammer travel,single impact energy presents an increasing trend,impact frequency presents a decreasing trend and impact power basically remains unchanged.Fourthly,with the increase of valve core weight,single impact energy presents an increasing trend,while both impact frequency and impact power decrease.Fifthly,the parameter combination corresponding to the optimal single impact energy and impact power is A5B1C5D4E3F2,and the effect of displacement on single impact energy and impact power is the greatest.It is concluded that under the existing displacement and pressure of drilling pumps,the impact performance of the hydraulic hammer can be increased effectively by improving the structure of the hydraulic hammer and thus increasing its work displacement.展开更多
基金Project supported by the National Natural Science Foundation of China(No.51805470)the Zhejiang Provincial Key Research&Development Project(No.2019C01025)and the Youth Funds of the State Key Laboratory of Fluid Power and Mechatronic Systems(Zhejiang University)(No.SKLoFP-QN-1801),China。
文摘In this paper,the piston type valve core and the unbalanced moment on its bottom are studied.To decrease the influence of non-common geometrical factors,a simplified model of the piston type globe valve is proposed in this study.Based on the computational fluid dynamics(CFD)method,the effects of different geometrical parameters on the unbalanced moment existing on the bottom of the valve core,which include the bending radius of the inlet flow channel,the diameter of the special-shaped pipe,and the height of the valve core,are studied.Finally,the effects of geometrical parameters on the unbalanced moment on the bottom of the valve core are clarified by correction and variation classification and provide a basis for further optimizing the structure of the piston type valve.The results show that the unbalanced moment decreases with the increase of the bending radius of the inlet flow channel,but increases with the increase of the diameter of the special-shaped pipe and the height of the valve core.Moreover,the relation between the unbalanced moment and flow rate is proposed.
基金supported by the National Key Research and Development Program of China(No.2021YFB2011300)the National Natural Science Foundation of China(No.52175067).
文摘External contamination particles or wear particles corroded by a valve body are mixed into the fluid. As a result, when the fluid enters the fitting clearance of the valve core, it can cause an increase in resistance and lead to sticking failure of the valve core. This paper analyzes solid-liquid flow characteristics in fitting clearances and valve-core sticking based on the Euler-Euler model, using a typical hydraulic valve as an example. The impact of particle concentration and diameter on flow characteristics and valve-core sticking force was analyzed. The highest volume fraction of particles was in the pressureequalizing groove(PEG), with peak values increasing as the particle diameter increased. The sticking force increased with increasing particle concentration. When the particle diameter was 12 μm, the sticking force was the largest, making this the sensitive particle diameter. Particle distribution and valve-core sticking force were compared for oval, rectangular, and triangular PEGs. The fluid-deflection angles in oval and rectangular PEGs were larger, and their values were 32.83° and 39.15°, respectively. The fluid-deflection angle in the triangular PEG was relatively small, less than 50% that of the oval or rectangular PEGs. The particle-volume-fraction peaks in oval, rectangular, and triangular PEGs were 0.0317, 0.0316, and 0.0312, respectively. The sticking forces of oval, rectangular, and triangular PEGs were 4.796, 4.802, and 4.757 N, respectively when the particle diameter was 12 μm. This work provides a reference for design and research aimed at reducing valve-core sticking.
基金supported by CNPC Scientific Research and Technology Development Project“Study on New Drilling Techniques and Methods”(No.2014A-4211).
文摘A YDC type hydraulic hammer is a new valve-type double action hydraulic hammer suitable for oil and gas well drilling.It is hard to find out the optimal matching relationship among various factors based on experience and experiments,for the matching relationships of inner pressure is complex and the impact performance is influenced by many factors.In this paper,the operating principle of a YDC type hydraulic hammer was investigated,the force applied to the main moving components(valve core and hammer)was analyzed and a dynamic model of valve core and hammer in each operating stage was established.Then,a hydraulic hammer performance optimization design software was developed on the Matlab software platform,and the performance parameters calculated by the software were compared with the laboratory test results.The following research results were obtained.Firstly,single impact energy,impact frequency and impact power increase with the increase of pump displacement or the decrease of flow bean diameter,and they increase firstly and then decrease with the increase of area difference between the upper and lower chambers.Secondly,with the increase of hammer weight,single impact energy and impact power increase,but the impact frequency decreases slowly.Thirdly,with the increase of hammer travel,single impact energy presents an increasing trend,impact frequency presents a decreasing trend and impact power basically remains unchanged.Fourthly,with the increase of valve core weight,single impact energy presents an increasing trend,while both impact frequency and impact power decrease.Fifthly,the parameter combination corresponding to the optimal single impact energy and impact power is A5B1C5D4E3F2,and the effect of displacement on single impact energy and impact power is the greatest.It is concluded that under the existing displacement and pressure of drilling pumps,the impact performance of the hydraulic hammer can be increased effectively by improving the structure of the hydraulic hammer and thus increasing its work displacement.
