scholarly journals A New Simulation Model for Vertical Spiral Ground Heat Exchangers Combining Cylindrical Source Model and Capacity Resistance Model

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1339 ◽  
Author(s):  
Takao Katsura ◽  
Takashi Higashitani ◽  
Yuzhi Fang ◽  
Yoshitaka Sakata ◽  
Katsunori Nagano ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Simulation Model ◽  
High Speed ◽  
Approximate Equation ◽  
Source Model ◽  
Calculation Model ◽  
Ground Heat Exchangers ◽  
Ground Source ◽  
Equivalent Length ◽  
Cylindrical Source

Considering the heat capacity inside vertical spiral ground heat exchanger (VSGHEX) in the simulation is one of the most noteworthy challenge to design the ground source heat pump (GSHP) system with VSGHEXs. In this paper, a new simulation model for VSGHEXs is developed by combining the ICS model with the CaRM. The developed simulation model can consider the heat capacity inside VSGHEX and provide dynamic calculation with high speed and appropriate precision. In order to apply the CaRM, the equivalent length was introduced. Then, the equivalent length was approximated by comparing the results of the CaRM and the numerical calculation. In addition, the calculation model of the VSGHEX was integrated into the design and simulation tool for the GSHP system. The accuracy of the tool was verified by comparing with the measurements. The error between supply temperatures of the measurements and calculation is approximately 2 °C at the maximum. Finally, assuming GSHP systems with VSGHEXs, whose spiral diameter was 500 mm and depth was 4 m, were installed in residential houses in Japan, the required numbers of VSGHEXs were estimated. The results showed a strong correlation between the total heating or cooling load and the required number. Therefore, the required number can be estimated by using the simplified approximate equation.

scholarly journals Research on heat transfer characteristics and borehole field layout of ground heat exchangers to alleviate thermal accumulation with groundwater advection

2021 ◽  
pp. 164-164
Author(s):  
Zhongcheng Sun ◽  
Zhixia He ◽  
Mingzhi Yu
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Source Model ◽  
Physical Parameters ◽  
Geological Condition ◽  
Ground Heat Exchanger ◽  
Heat Accumulation ◽  
Line Heat Source ◽  
Ground Heat Exchangers ◽  
Ground Source

The heat transfer performance of ground heat exchanger is significant to the ground source heat pump. The soil thermal parameters, the groundwater advection and the different borehole field layout are important factors to affect the performance of ground heat exchanger. Therefore, the influence of groundwater advection velocity, soil physical parameters and different borehole field layout on the soil temperature distribution and evolution around the ground heat exchanger has been analyzed and studied with unbalanced seasonal thermal load based on the moving finite line heat source model with groundwater advection. The results show that the heat accumulation is easy to occur as the time develops when the groundwater advection is taken into consideration. No matter what type of geological condition is employed, a reasonable borehole field layout can effectively avoid heat accumulation problems under the condition of keeping the same amount boreholes without changing the original ground area. The borehole field layout dispersed along the center line of the advection and concentrated in the advection downstream relatively can effectively reduce the heat accumulation.

scholarly journals Macro Modeling of V-Shaped Electro-Thermal MEMS Actuator with Human Error Factor

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 622
Author(s):  
Dongpeng Zhang ◽  
Anjiang Cai ◽  
Yulong Zhao ◽  
Tengjiang Hu
Keyword(s):  
Neural Network ◽  
Simulation Model ◽  
Bp Neural Network ◽  
Human Error ◽  
Calculation Model ◽  
Fuzzy Mathematics ◽  
Ansys Simulation ◽  
Macro Modeling ◽  
Error Factor ◽  
Simulation Results

The V-shaped electro-thermal MEMS actuator model, with the human error factor taken into account, is presented in this paper through the cascading ANSYS simulation model and the Fuzzy mathematics calculation model. The Fuzzy mathematics calculation model introduces the human error factor into the MEMS actuator model by using the BP neural network, which effectively reduces the error between ANSYS simulation results and experimental results to less than 1%. Meanwhile, the V-shaped electro-thermal MEMS actuator model, with the human error factor included, will become more accurate as the database of the V-shaped electro-thermal actuator model grows.

scholarly journals Influence of tool edge form factor and cutting parameters on milling performance

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110090
Author(s):  
Xuefeng Zhao ◽  
Hao Qin ◽  
Zhiguo Feng
Keyword(s):  
Form Factor ◽  
Simulation Model ◽  
Cutting Force ◽  
Surface Quality ◽  
High Speed ◽  
Orthogonal Cutting ◽  
Cutting Temperature ◽  
Tool Edge ◽  
Drag Finishing ◽  
Edge Preparation

Tool edge preparation can improve the tool life, as well as cutting performance and machined surface quality, meeting the requirements of high-speed and high-efficiency cutting. In general, prepared tool edges could be divided into symmetric or asymmetric edges. In the present study, the cemented carbide tools were initially edge prepared through drag finishing. The simulation model of the carbide cemented tool milling steel was established through Deform software. Effects of edge form factor, spindle speed, feed per tooth, axial, and radial cutting depth on the cutting force, the tool wear, the cutting temperature, and the surface quality were investigated through the orthogonal cutting simulation. The simulated cutting force results were compared to the results obtained from the orthogonal milling experiment through the dynamometer Kistler, which verified the simulation model correctness. The obtained results provided a basis for edge preparation effect along with high-speed and high effective cutting machining comprehension.

Novel Manchester-Based Multilevel Signaling for High-Speed Optical Communication Systems

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Festus Idowu Oluwajobi ◽  
Nguyen Dong-Nhat ◽  
Amin Malekmohammadi
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Chromatic Dispersion ◽  
Optical Fiber Communication ◽  
Pulse Amplitude ◽  
Calculation Model ◽  
Fiber Communication ◽  
Receiver Sensitivity ◽  
Communication Links ◽  
Dispersion Tolerance

AbstractIn this paper, the performance of a novel multilevel signaling based on Manchester code namely four-level Manchester Coding (4-MC) technique is investigated for next generation high-speed optical fiber communication links. The performance of 4-MC is studied and compared with conventional Manchester modulation and four-level pulse amplitude modulation (4-PAM) formats in terms of receiver sensitivity, spectral efficiency and dispersion tolerance at the bit rate of 40 Gb/s. The bit error rate (BER) calculation model for the proposed multilevel scheme has also been developed. The calculated receiver sensitivity and the chromatic dispersion tolerance at the BER of 10–9 of the proposed scheme are −22 dBm and 67.5 ps/nm, respectively. It is observed that, 4-MC scheme is superior in comparison to 4-PAM by 3.5 dB in terms of receiver sensitivity in back-to-back scenario. Therefore, the proposed scheme can be considered as an alternative to current 4-PAM system.

Simulation on the Regulating Characteristics of the Pulse Modulation Hydraulic Hammer

2011 ◽  
Vol 422 ◽  
pp. 176-183
Author(s):  
Gang Wang ◽  
Yu Wan Cen
Keyword(s):  
Time Delay ◽  
Simulation Model ◽  
Impact Energy ◽  
High Speed ◽  
Impact Frequency ◽  
Pulse Modulation ◽  
Motion Equations ◽  
Hydraulic Hammer ◽  
Working Frequency ◽  
Simulation Results

To improve the regulating characteristics of impact energy, simplify structure of hydraulic hammer, a new pulse modulation hydraulic hammer is presented in the paper which can help regulate its impact frequency easily. The motion equations of the hydraulic hammer are established, its simulation model is obtained and the dynamic simulation is carried out on AMESim. The dynamics of high-speed ON/OFF valve is taken into account in the simulation model. The tendency of simulation results conforms to experimental results; it shows that the pulse modulation hydraulic hammer is feasible, and the hydraulic hammer model is reasonable. The time delay in high working frequency is also analyzed.

Stochastic Transverse Earthquake-Induced Damage Track Irregularity Spectrum Considering the Uncertainty of Track-Bridge System

2021 ◽  
pp. 2140004
Author(s):  
Yulin Feng ◽  
Yu Hou ◽  
Lizhong Jiang ◽  
Wangbao Zhou ◽  
Jian Yu ◽  
...  
Keyword(s):  
Simulation Model ◽  
Traffic Safety ◽  
High Speed ◽  
Residual Deformation ◽  
High Speed Railway ◽  
Marquardt Algorithm ◽  
Earthquake Action ◽  
Track Irregularity ◽  
Track Bridge ◽  
Bridge System

The track irregularity spectrum of longitudinally connected ballastless track (LCBT)-bridge systems of high-speed railway was proposed in this paper. First, a simulation model of an LCBT-continuous girder bridge was established by considering the influences of approach bridges and subgrade with track structure. Further, a large number of sample analyses were carried out by taking into account the uncertainty of LCBT-bridge systems and stochastic behaviors of ground motions based on the simulation model. The damage laws of residual deformation of track-bridge system after earthquake actions were studied. Then, an interlayer deformation coordination relationship (IDCR) considering the track irregularity caused by earthquake-induced damage of bearings was developed, and the superposed track irregularity samples were obtained. Finally, by using the improved Blackman–Turkey method and Levenberg–Marquardt algorithm, the LCBT irregularity spectrum, track irregularity spectrogram, track irregularity limit spectrum, and a fitting formula for the track irregularity spectrum on a bridge after the action of earthquakes were obtained. Results obtained from the fitting formula and IDCR were compared, and they indicated that tracks undergone significant high-frequency irregularity diseases after the earthquake action. It was found that the track irregularity spectrum could be roughly divided into three ranges: high-, medium- and low-frequency wavebands. Consequently, this led to an application of a three-segment power function for the fitting of the track irregularity spectrum after the earthquake action. The track irregularity spectrum after the action of earthquakes provides an important theoretical basis for the establishment of seismic design methods for high-speed railway bridges based on the traffic safety performance.

scholarly journals Driving Torque Model and Accuracy Test of Multilink High-Speed Punch

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fuxing Li ◽  
Hao Liu ◽  
Menglei Li ◽  
Jun Guo ◽  
Xinjian Lu ◽  
...  
Keyword(s):  
High Speed ◽  
Calculation Model ◽  
Effective Control ◽  
Inertia Force ◽  
Conservation Of Energy ◽  
Accuracy Test ◽  
Operation Stability ◽  
Strategy Planning ◽  
The Stability ◽  
Driving Torque

Inertia force is an important factor for operation stability and stamping precision of high-speed punch; adjusting drive torque of high-speed punch can realize effective control of inertia force. In this paper, a kind of 600 KN multilink high-speed punch inertia force balancing mechanism was designed. The calculation model of ideal inertia force was proposed based on conservation of energy and numerical analysis method. In addition, the calculation model of ideal driving torque were analyzed, simplified, and corrected by using numerical calculation and simulation methods, which solved the problem of controlling inertia force from the perspective of driving torque and realized the stability strategy planning of high-speed multilink punch press. Finally, the proposed ideal driving torque calculation model was simulated and verified by ADAMAS and bottom-dead-point accuracy test was carried out.

A study of modeling experiments of the vibration behavior of elevated railway box girder

2018 ◽  
Vol 25 (5) ◽  
pp. 984-995 ◽  
Author(s):  
Kun Luo ◽  
Xiaoyan Lei
Keyword(s):  
High Speed ◽  
Similarity Theory ◽  
Longitudinal Direction ◽  
Calculation Model ◽  
Scale Model ◽  
Box Girder ◽  
Vibration Transmissibility ◽  
Girder Bridge ◽  
Structure Simplification ◽  
Model Similarity

Based on the model similarity theory, this article deduces the model similarity relationship of the elevated railway box girder at the elastic stage and designs a 1/10 box girder scale model by adopting a 32 m simply-supported box girder bridge from the Beijing–Shanghai Railway as the prototype. It then verifies the validity of the model design and the dynamic similarity between the 1/10 model and the prototype through constraint mode and free mode experiments on the 1/10 scale model, together with transient finite element calculation. The dynamic calculation model is utilized here for the analysis of the errors occurring in the production of the model, and the effect of the model structure simplification on the box girder mode frequency and vibration response. Finally, the article studies the vibration transmissibility characteristics between the plates and along the longitudinal direction by means of model testing. It also discusses the effect of different bridge support stiffness on the box girder vibration. The results presented in this paper can provide a method for forecasting and evaluating the existing or plan-to-build high speed railway environment vibration.

scholarly journals Intelligent Calculation Model and Algorithm Optimization of Optimal Operation of Integrated Energy System

2021 ◽  
Vol 2083 (3) ◽  
pp. 032033
Author(s):  
Kun Wang ◽  
Guochao Yang ◽  
Baohua Cheng ◽  
Zhiyong Gan ◽  
Yan Qi ◽  
...  
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Energy System ◽  
Calculation Model ◽  
Optimal Operation ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source ◽  
Saving Effect

Abstract This paper analyzes the energy saving effect and optimal operation of the integrated park type energy system. The park type integrated energy system includes photovoltaic power generation system, ground source heat pump system, solar air conditioning system, regenerative electric boiler system and solar hot water system and so on. The energy saving benefit calculation model of each subsystem is established, and according to the operation history data of each subsystem, the calculation results of each subsystem are analyzed. It shows that: The energy saving income of photovoltaic power generation system is 734,200 yuan/year. The main revenue comes from the second and third quarters, during which it should pay attention to the maintenance of photovoltaic modules to ensure the maximum energy saving benefit. The energy saving income of ground source heat pump system in summer is 155,900 yuan/year, and the energy saving effect is not significant. It can cooperate with traditional units for cooling in summer. The heating in winter in the park is provided by ground source heat pump system, regenerative electric boiler system and solar energy air conditioning system. Its energy saving benefit is 3.995 million yuan/year which is the main source of energy saving income in the park, with remarkable energy saving effect.

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