calculation model
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2022 ◽  
Vol 9 ◽  
Author(s):  
Zhengdian Xu ◽  
Hong Li ◽  
Yue Jiang ◽  
Qingjiang Xiang ◽  
Pan Tang

To solve the problems of higher energy consumption and lower intelligence of traditional hard hose travelers, a new hard hose traveler with the function of electric drive and self-propelled is developed in this paper. The operational energy consumption of a reel and a polyethylene tube is an important part of hard-hose traveler energy consumption. In this paper, based on the JP50-180 hard hose traveler, the required pulling force and energy consumption at the reel and tube operation are theoretically and experimentally obtained. The aforementioned provides support for reducing energy consumption in the future. The influencing factor that affects the energy consumption of the reel rotation is the tube length, and the influencing factors that affect the energy consumption of the tube sliding are the ground slope, soil moisture content, and tube length. A calculation model for the dynamic change of the pulling force and energy consumption of the reel and tube operation is proposed in this study. Through theoretical analysis, maximum pulling tension and cumulative energy consumption requirements for the for reel rotation are 278.6 N and 15120.83 J, respectively. Furthermore, the requirements for the tube sliding are 1372.86 N and 123,456.96 J. Through test analysis, the maximum pulling tension for the tube sliding is between 1258.3 N and 1773.3 N, while the maximum pulling tension for reel rotation is 285.05 N. Under the same influencing factors, the deviation rates between theoretical and testable energy consumption for the reel rotation and tube sliding are 2.3 and 8.3%, respectively. The pulling force and cumulative energy consumption required for the reel rotation and tube sliding both increase with an increase in their influencing factors. The operating costs of the tube one-time unrolled are approximately 0.0185 CNY. Combined with the mobile resistance of the electric tracked vehicle, the power configuration of this new hard hose traveler is provided by two servo motors with a power of 5500 W each.


2022 ◽  
Author(s):  
Qianli Lu ◽  
Zhuang Liu ◽  
Jianchun Guo ◽  
Shouyi Wang ◽  
Le He ◽  
...  

Abstract Casing deformation (CD) is a major challenge for shale gas development in Weiyuan gasfield, natural fracture (NF) slippage is one of the main causes of CD in Weiyuan gas filed. In order to study the mechanism and regularity of NF slippage induced CD, a wellbore shear stress calculation model and a CD degree prediction model are established. And results show that, the approach angle and ground principal stress difference have significant influence on wellbore shear stress, high wellbore shear stress occurs when wellbore orientation is perpendicular to the NF trend. Wellbore shear stress increases with the increase of fracture fluid pressure and NF area, improving casing strength or cementing quality has limited effect on reducing the risk of CD. The smaller the young's modulus, the higher the CD degree, Poisson's ratio has limited effect on CD degree. NF approach and fracture fluid pressure determines the value of CD degree. Field case shows that reasonable fracturing technology to control fracture net pressure and wellbore position arrangement are helpful for reducing CD risk, and the model proposed in this paper can be used to predict CD risk and calculate the CD degree.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Chuan-yang Liang ◽  
Yue-dong Wu ◽  
Jian Liu ◽  
Lei Zhang ◽  
Lai-he Lin ◽  
...  

AbstractThe difference in the shear strength and other characteristics of the cohesive soil containing calcareous nodules (CSCN) between samples with large size and corresponding scaling size, which is called scaling effect, is significantly affected by its calcareous nodule content (CNC) of the gradation composition. However, current researches rarely reveal the influence of the CNC on the scaling effect in shear strength of samples. In this study, how and why the CNC affects the scaling effect in shear strength were explored. Then a method to reduce the scaling effect based on the reason for influence was proposed. Results show that the correlation between the scaling effect in shear strength and the CNC presents a step curve. This is attributed to that it is easier to form a skeleton effect in samples with scaling size for the same CNC. Considering the skeleton effect, a calculation model for the shear strength parameters of CSCN samples with large size is proposed to reduce the scaling effect. This paper demonstrates that the proposed calculation model provides an access to obtain calculated shear strength parameters of CSCN samples with large size by using measured results of samples with corresponding scaling size.


Geofluids ◽  
2022 ◽  
Vol 2022 ◽  
pp. 1-9
Author(s):  
Dahai Wang ◽  
Jinbu Li ◽  
Lili Liu ◽  
Ji Zhang ◽  
Zhanhai Yu ◽  
...  

The value of a cementation exponent, usually obtained by rock and electricity experiments, significantly affects the calculation of water saturation, thickness of the hydrocarbon reservoir, and recovery rate. The determination of the cementation exponent for porous-media reservoirs has been a challenge because of the limited core sampling. A new method was proposed to determine the value of cementation exponent for complex triple-porosity media reservoirs in the work. Firstly, the work discussed the effects of fractures and nonconnected vugs on the cementation exponent of the reservoir as well as the calculation method of the cementation exponent of the dual-porosity media reservoir. Then, a new model for calculating the cementation exponent of triple-porosity media reservoirs was derived by combining the Maxwell-Garnett theory and series-parallel theory, which matched with the real physical-experiment data of rocks. The results showed that the fractures decreased the cementation exponent of the reservoir but the vugs increased. The mixture of matrix pores, fractures, and vugs made the value of the cementation exponent of the triple-porosity media reservoir vary around 2.0. The conductivity of the triple-porosity media reservoir was the external macroscopic expression of the microscopic conductive network. The new calculation model of the cementation exponent proposed in the work could reasonably predict the cementation exponent of the strongly inhomogeneous triple-porosity media reservoir.


2022 ◽  
Vol 14 (2) ◽  
pp. 629
Author(s):  
Fu Wang ◽  
Dengjun Gu ◽  
Anqi Chen

Many cities have built expressways to alleviate traffic congestion, among which elevated expressways are the most common form. However, traffic congestion still occurs frequently in the connecting section between the ramp of expressway and the ground intersection. Based on the field traffic survey data, the traffic operation characteristics of vehicles in the connecting section and the main factors affecting the length of the connecting section are analyzed. A combined model for calculating the length of the connecting section between ramp of urban expressway and intersection is proposed. VISSIM is used to simulate the traffic flow under the current and calculated length of the connecting section. The comparison results show that under the calculation length, the travel time, average delay, parking time and queue length are reduced to varying degrees, which verifies the rationality of the calculation model.


Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 392
Author(s):  
Shuhan Hu ◽  
Hongyuan Chen

Many countries, especially China, have extensively promoted liquefied natural gas (LNG) to replace diesel in heavy-duty vehicles for to achieve sustainable transport aims, including carbon peaks and neutrality. We developed a life-cycle calculation model for environmental load differences covering vehicle and fuel cycles to comprehensively compare the LNG tractor-trailer and its diesel counterpart in China on a full suite of environmental impacts. We found that the LNG tractor-trailer consumes less aluminum but more iron and energy; emits less nitrogen oxide, sulfur oxide, nonmethane volatile organic compounds, and particulate matter but more greenhouse gases (GHG) and carbon monoxide (CO); and causes less abiotic depletion potential, acidification potential, and human toxicity potential impacts but more global warming potential (GWP) and photooxidant creation potential (POCP) impacts. Poor fuel economy was found to largely drive the higher life-cycle GHG and CO emissions and GWP and POCP impacts of the LNG tractor-trailer. Switching to the LNG tractor-trailer could reduce carbon dioxide by 52.73%, GWP impact by 44.60% and POCP impact by 49.23% if it attains parity fuel economy with its diesel counterpart. Policymakers should modify the regulations on fuel tax and vehicle access, which discourage improvement in LNG engine efficiency and adopt incentive polices to develop the technologies.


2022 ◽  
Vol 905 ◽  
pp. 314-319
Author(s):  
Lin Liu ◽  
Jing Chang Wang

In order to study the influence of water content and hydration degree on the thermal conductivity of concrete, based on the steady-state plate method, the influence of water content, temperature, hydration degree and other factors on the thermal conductivity of early concrete was studied, and the calculation model of thermal conductivity of early concrete was established according to the test results and influence rules. The results show that there is a linear relationship between the thermal conductivity and water content at 28d, the higher the hydration degree is, the lower the thermal conductivity of concrete is; the difference between the measured value and the calculated model value is small, and the calculation formula can meet the requirements of engineering calculation.


2022 ◽  
Vol 355 ◽  
pp. 03071
Author(s):  
Gang Liu ◽  
Guang Yu ◽  
Qingyuan Xue

It is not easy to carry out the detailed variable condition calculation of steam turbine in engineering application. In this paper, a variable condition calculation model based on the internal and external characteristics of steam turbine is proposed, and a variable condition calculation model of constant power and constant flow is established. The model is applied to calculate 75% THA, 50%THA, typical industrial and heating extraction conditions of a subcritical 330 MW unit. The error is small compared with the design value, and the calculation accuracy meets the requirements. The results show that the model has high accuracy and can meet the requirements of engineering application.


2022 ◽  
Vol 334 ◽  
pp. 03002
Author(s):  
Maria Alessandra Ancona ◽  
Michele Bianchi ◽  
Lisa Branchini ◽  
Francesco Catena ◽  
Andrea De Pascale ◽  
...  

The integration of renewable energy sources into the electricity system can contribute to the development of a low-carbon economy. However, due to the intermittency and non-programmability of these sources, problems related to the management of local electricity grids may occur. A possible solution or limitation to these issues is given by the electrical storage. In addition, in the next future, domestic micro-grids are expected to play a fundamental role in electric power networks, driving both the academic and industrial research interests in developing highly efficient and reliable conversion and storage technologies. In this study, the behavior of a small-scale hybrid energy system for hydrogen production and storage has been predicted, by means of a developed calculation model, and the operational strategy of the system has been optimized with the aim to maximize the hydrogen production. In addition, with the aim to maximize the overall solar-to-hydrogen chain efficiency, the whole system model has been applied to different operating scenarios, to identify the optimal management strategy to control it.


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