Nowadays,the limits on greenhouse gas emissions are becoming increasingly stringent.In present research,a two-dimensional numerical model was established to simulate the deep removal of 1,1,1,2-tetrafluoroethane(R134a...Nowadays,the limits on greenhouse gas emissions are becoming increasingly stringent.In present research,a two-dimensional numerical model was established to simulate the deep removal of 1,1,1,2-tetrafluoroethane(R134a)from the non-condensable gas(NCG)mixture by cryogenic condensation and de-sublimation.The wall condensation method was compiled into the Fluent software to calculate the condensation of R134a from the gas mixture.Besides,the saturated thermodynamic properties of R134a under its triple point were extrapolated by the equation of state.The simulation of the steam condensation with NCG was conducted to verify the validity of the model,the results matched well with the experimental data.Subsequently,the condensation characteristics of R134a with NCG and the thermodynamic parameters affecting condensation were studied.The results show that the section with relatively higher removal efficiency is usually near the inlet.The cold wall temperature has a great influence on the R134a removal performance,e.g.,a 15 K reduction of the wall temperature brings a reduction in the outlet R134a molar fraction by 85.43%.The effect of changing mass flow rate on R134a removal is mainly reflected at the outlet,where an increase in mass flow rate of 12.6% can aggravate the outlet molar fraction to 210.3% of the original.The research can provide a valuable reference for the simulation of the deep removal of various low-concentration gas using condensation and de-sublimation methods.展开更多
The research about subsurface characteristics by using transient electromagnetic method(TEM) and high density resistivity method(HDRM) were already conducted in Ordos. The objective of this research is to detect c...The research about subsurface characteristics by using transient electromagnetic method(TEM) and high density resistivity method(HDRM) were already conducted in Ordos. The objective of this research is to detect coalmine goaf areas based on rock resistivity. The data processing using wavelet transform, three point smoothing, RES2 DINV and Maxwell processing software to obtain 2D resistivity structure. The results showed that the layers with maximum resistivity values(30e33 U m on Line 1, 30e31 U m on Line 2, 32e40 U m on Line3) are founded at station 1e7, and 14e20 on Line 1,13e18 on Line 2, and 8e13 and 16e20 on Line 3 which is predicted as goaf layer, and the minimum resistivity values(20e26 U m of TEM, 45e75 U m of HDRM) at the other layers. This resistivity difference was caused by the geology and characteristics of the study area which is located close by the cleugh with rich coal, so the goaf area distinguishable with aquifer layer and coal seam. The results were also significant accidents and serious destruction of ecological environment.展开更多
In this paper, we calculated Bouguer gravity anomalies and Airy-Heiskanen isostatic anomalies in the New Britain Trench and surrounding areas of Papua New Guinea. The calculations are based on a topographic model and ...In this paper, we calculated Bouguer gravity anomalies and Airy-Heiskanen isostatic anomalies in the New Britain Trench and surrounding areas of Papua New Guinea. The calculations are based on a topographic model and a gravity anomaly model from the Scripps Institute of Oceanography. Characteristics of the isostatic anomaly and the earthquake dynamic environment of this region are analyzed,and the results show that there are obvious differences in the isostatic state between each block in the region. Tectonic movements are very intense in regions with high positive or negative isostatic gravity anomalies, and a number of sub-plates in this area are driven by external tectonic action, such as plate subduction and thrusting, of the Pacific, Indo-Australian and Eurasian plates. From the distribution of the isostatic gravity anomaly, the tectonic action of anti-isostatic movement obviously is the main source of power. Based on isostatic gravity and spatial distribution of earthquakes in the region, it is obvious that further contraction of the Indo-Australian Plate will result in the southwestern part of the Solomon Plate becoming part of the Owen Stanley thrust belt, and the northern part will enter the lower part of the Bismarck Plate. The eastern part of the Solomon Plate will enter the front of the Pacific Plate, resulting in northward and eastward migration of significant earthquakes along the Solomon Plate.展开更多
This paper deals with the interpretation of Bouguer gravity anomalies measured along a 250 km long Suhaitu-Etuokeqi gravity profile located at the transitional zone of the Alxa and Ordos blocks where geophysical chara...This paper deals with the interpretation of Bouguer gravity anomalies measured along a 250 km long Suhaitu-Etuokeqi gravity profile located at the transitional zone of the Alxa and Ordos blocks where geophysical characteristics are very complex. The analysis is carried out in terms of the ratio of elevation and Bouguer gravity anomaly, the normalized full gradient of a section of the Bouguer gravity anomaly (Gh) and the crustal density structure reveal that (1) the ratio of highs and lows of elevation and Bouguer gravity anomaly is large between Zhengyiguan fault (F4) and Helandonglu fault (F6), which can be explained due to crustal inhomogeneities related to the uplift of the Qinghai-Tibet block in the northeast; (2) the main active faults correspond to the Gh contour strip or cut the local region, and generally show strong deformation characteristics, for example the Bayanwulashan mountain front fault (F1) or the southeast boundary of Alxa block is in accord with the western change belt of Gh, a belt about 10 km wide that extends to about 30 km; (3) Yinchuan- Pingluo fault (FS) is the seismogenic structure of the Pin- gluo M earthquake, and its focal depth is about 15 km; (4) the Moho depth trend and Bouguer gravity anomaly vari- ation indicates that the regional gravity field is strongly correlated with the Moho discontinuity.展开更多
The study of postseismic deformation is important for constraining the viscoelastic properties of the Earth and inverting the post-earthquake process.The levelling survey revealed that the area near Bei-chuan elevated...The study of postseismic deformation is important for constraining the viscoelastic properties of the Earth and inverting the post-earthquake process.The levelling survey revealed that the area near Bei-chuan elevated 5.3 cm about two years after the M_(W) 7.9 Wenchuan earthquake(05/12/2008),during which the area underwent significant downward movement.The GPS horizontal displacements showed a non-monotonic variation after the Wenchuan earthquake.In this study,a 3-D viscoelastic finite element model is employed to simulate the coseismic and postseismic deformation of the Wenchuan earthquake.The numerical simulations show that the lateral heterogeneity across the Longmenshan fault plays an important role in the postseismic displacements.The results reveal that the coseismic defor-mation is not sensitive to the horizontal heterogeneity,but the postseismic deformation is sensitive to it.The postseismic deformation of the horizontally heterogeneous model is generally consistent with the observations of all geodetic surveys,such as GPS,InSAR and levelling,but not for the horizontally homogenous model.We also find that the non-monotonous variation of the postseismic deformation of the Wenchuan earthquake could be explained by a viscoelastic relaxation model with lateral heterogeneous medium across the Longmenshan fault.展开更多
In this paper,we present an open python procedure with Jupyter notebook,for data extraction and vectorization of geophysical explo ration profile.Constrained by observation routes and traffic conditions,geophysical ex...In this paper,we present an open python procedure with Jupyter notebook,for data extraction and vectorization of geophysical explo ration profile.Constrained by observation routes and traffic conditions,geophysical exploration profiles tend to bend curved roads for easy observation,however,it must be projected onto a straight line when data processing and analyzing.After projection,we don’t know the true position of the obtained crustal structure.Nonetheless,when the results used as an initial constraint condition for other geophysical inversion,such as gravity inversion,we need to know the true position of the data rather than the distance to the starting point.We solved this problem by profile vectorization and reprojection.The method can be used for extraction data of various geophysical exploration profiles,such as seismic reflection profiles,gravity profiles.展开更多
Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia.In this paper,taking advantage of a ...Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia.In this paper,taking advantage of a unique network of gravity tidal stations all over the Chinese mainland,we compare the observed and modeled tidal loading effects on the basis of the most recent global ocean tide models.The results show that the average efficiencies of the ocean tidal loading correction for O_(1),K_(1),M_(2) are 77%,7 s3%and 59%,respectively.The loading correction efficiencies using recent ocean tidal models are better than the 40 years old Schwiderskis model at coastal stations,but relative worse at stations far from ocean.展开更多
Cryogenic energy storage(CES)is a viable method for grid-scale electrical energy storage.Considering the high energy density and mature application of liquefied natural gas(LNG),we proposed an LNG cryogenic energy sto...Cryogenic energy storage(CES)is a viable method for grid-scale electrical energy storage.Considering the high energy density and mature application of liquefied natural gas(LNG),we proposed an LNG cryogenic energy storage(LNGES)system.A steady-state process model of the LNGES system was established using Aspen HYSYS.The effects of the natural gas composition and key operating parameters such as the charging pressure,discharging pressure,throttling temperature,and liquid storage pressure on the system performance were investigated.A multi-parameter genetic algorithm model built using the MATLAB software was used to optimize the LNGES system to optimize the round-trip efficiency(RTE).Then,an exergy analysis of the optimal configuration was conducted.The results suggested that the LNGES system could achieve optimal RTE and exergy efficiency values of 60.14%and 71.64%,respectively.Exergy destruction mainly occurred during the compression,throttling,expansion,and heat exchange.The proposed LNGES system could be a promising candidate for the large-scale application of CES technology in power grids and gas networks.展开更多
Cryogenic energy storage(CES)has garnered attention as a large-scale electric energy storage technology for the storage and regulation of intermittent renewable electric energy in power networks.Nitrogen and argon can...Cryogenic energy storage(CES)has garnered attention as a large-scale electric energy storage technology for the storage and regulation of intermittent renewable electric energy in power networks.Nitrogen and argon can be found in the air,whereas methane is the primary component of natural gas,an important clean energy resource.Most research on CES focuses on liquid air energy storage(LAES),with its typical round-trip efficiency(RTE)being approximately 50%(theoretical).This study aims to explore the feasibility of using different gases as working media in CES systems,and consequently,to achieve a high system efficiency by constructing four steady-state process models for the CES systems with air,nitrogen,argon,and methane as working media using Aspen HYSYS.A combined single-parameter analysis and multi-parameter global optimization method was used for system optimization.Further,a group of key independent variables were analysed carefully to determine their reasonable ranges to achieve the ideal system performance,that is,RTE and liquefaction ratio through a single-parameter analysis.Consequently,a multi-parameter genetic algorithm was adopted to globally optimize the CES systems with different working media,and the energy and exergy analyses were conducted for the CES systems under their optimal conditions.The results indicated the high cycle efficiency of methane and a low irreversible loss in the liquefaction cycle.Moreover,the Joule-Thomson valve inlet temperature and charging and discharging pressures considerably affected the system performance.However,exergy loss in the CES system occurred primarily in the compressor,turbine,and liquefaction processes.The maximum optimal RTE of 55.84%was achieved in the liquid methane energy storage(LMES)system.Therefore,the LMES system is expected to exhibit potential for application in the CES technology to realize the integration of natural gas pipelines with renewable power grids on a large scale.Moreover,the results of study have important theoretical significance for the innovation of the CES technology.展开更多
Flexible gas power plants are subject to energy storage,peak regulations,and greenhouse gas emissions.This study proposes an integrated power generation system that combines liquid air energy storage(LAES),liquefied n...Flexible gas power plants are subject to energy storage,peak regulations,and greenhouse gas emissions.This study proposes an integrated power generation system that combines liquid air energy storage(LAES),liquefied natural gas(LNG)cold energy utilization,gas power systems,and CO_(2) capture and storage(CCS)technologies,named the LAES-LNG-CCS system.The off-peak electricity can be stored in liquid air.During the peak period,air and gas turbines generate supplementary electricity.Both LNG chemical energy and cold energy were considered:the former was used for gas power plants,and the latter was used for LAES regasification and CCS processes.Based on the thermodynamic analysis,we evaluated the effects of the recovery pressure,CCS pressure,and combustion temperature on the system power consumption and efficiency.The results demonstrated that the system recovery pressure,CCS pressure,and combustion temperature had the greatest effects on system power generation.Round-trip efficiency(RTE)was significantly affected by combustion temperature.The largest exergy loss occurred in the gas power plant.The optimal system operating ranges of the system recovery pressure,CCS pressure,and combustion temperature were 6−10 MPa,0.53−0.8 MPa,and 1,503−1,773 K,where the RTEs and𝜂Ex,RS reached 55%−58.98%and 74.6%−76%,respectively.The proposed system can simultaneously achieve the synergistic functions of large-scale energy storage,multilevel energy utilization,peak regulation,and carbon emission reduction.It can also be widely used in advanced distributed energy storage applications in the future.展开更多
基金funded by the National Natural Science Foundation of China(52076159)。
文摘Nowadays,the limits on greenhouse gas emissions are becoming increasingly stringent.In present research,a two-dimensional numerical model was established to simulate the deep removal of 1,1,1,2-tetrafluoroethane(R134a)from the non-condensable gas(NCG)mixture by cryogenic condensation and de-sublimation.The wall condensation method was compiled into the Fluent software to calculate the condensation of R134a from the gas mixture.Besides,the saturated thermodynamic properties of R134a under its triple point were extrapolated by the equation of state.The simulation of the steam condensation with NCG was conducted to verify the validity of the model,the results matched well with the experimental data.Subsequently,the condensation characteristics of R134a with NCG and the thermodynamic parameters affecting condensation were studied.The results show that the section with relatively higher removal efficiency is usually near the inlet.The cold wall temperature has a great influence on the R134a removal performance,e.g.,a 15 K reduction of the wall temperature brings a reduction in the outlet R134a molar fraction by 85.43%.The effect of changing mass flow rate on R134a removal is mainly reflected at the outlet,where an increase in mass flow rate of 12.6% can aggravate the outlet molar fraction to 210.3% of the original.The research can provide a valuable reference for the simulation of the deep removal of various low-concentration gas using condensation and de-sublimation methods.
基金supported by the Institute of Seismology Foundation, China Earthquake Administration (201326126)
文摘The research about subsurface characteristics by using transient electromagnetic method(TEM) and high density resistivity method(HDRM) were already conducted in Ordos. The objective of this research is to detect coalmine goaf areas based on rock resistivity. The data processing using wavelet transform, three point smoothing, RES2 DINV and Maxwell processing software to obtain 2D resistivity structure. The results showed that the layers with maximum resistivity values(30e33 U m on Line 1, 30e31 U m on Line 2, 32e40 U m on Line3) are founded at station 1e7, and 14e20 on Line 1,13e18 on Line 2, and 8e13 and 16e20 on Line 3 which is predicted as goaf layer, and the minimum resistivity values(20e26 U m of TEM, 45e75 U m of HDRM) at the other layers. This resistivity difference was caused by the geology and characteristics of the study area which is located close by the cleugh with rich coal, so the goaf area distinguishable with aquifer layer and coal seam. The results were also significant accidents and serious destruction of ecological environment.
基金supported by the Science for Earthquake Resilience(XH17022)
文摘In this paper, we calculated Bouguer gravity anomalies and Airy-Heiskanen isostatic anomalies in the New Britain Trench and surrounding areas of Papua New Guinea. The calculations are based on a topographic model and a gravity anomaly model from the Scripps Institute of Oceanography. Characteristics of the isostatic anomaly and the earthquake dynamic environment of this region are analyzed,and the results show that there are obvious differences in the isostatic state between each block in the region. Tectonic movements are very intense in regions with high positive or negative isostatic gravity anomalies, and a number of sub-plates in this area are driven by external tectonic action, such as plate subduction and thrusting, of the Pacific, Indo-Australian and Eurasian plates. From the distribution of the isostatic gravity anomaly, the tectonic action of anti-isostatic movement obviously is the main source of power. Based on isostatic gravity and spatial distribution of earthquakes in the region, it is obvious that further contraction of the Indo-Australian Plate will result in the southwestern part of the Solomon Plate becoming part of the Owen Stanley thrust belt, and the northern part will enter the lower part of the Bismarck Plate. The eastern part of the Solomon Plate will enter the front of the Pacific Plate, resulting in northward and eastward migration of significant earthquakes along the Solomon Plate.
基金supported by the Key Projects of China Seismic Array(201308011)Earthquake Science(201508006)the China Earthquake Administration,Institute of Seismology Foundation(201326126)
文摘This paper deals with the interpretation of Bouguer gravity anomalies measured along a 250 km long Suhaitu-Etuokeqi gravity profile located at the transitional zone of the Alxa and Ordos blocks where geophysical characteristics are very complex. The analysis is carried out in terms of the ratio of elevation and Bouguer gravity anomaly, the normalized full gradient of a section of the Bouguer gravity anomaly (Gh) and the crustal density structure reveal that (1) the ratio of highs and lows of elevation and Bouguer gravity anomaly is large between Zhengyiguan fault (F4) and Helandonglu fault (F6), which can be explained due to crustal inhomogeneities related to the uplift of the Qinghai-Tibet block in the northeast; (2) the main active faults correspond to the Gh contour strip or cut the local region, and generally show strong deformation characteristics, for example the Bayanwulashan mountain front fault (F1) or the southeast boundary of Alxa block is in accord with the western change belt of Gh, a belt about 10 km wide that extends to about 30 km; (3) Yinchuan- Pingluo fault (FS) is the seismogenic structure of the Pin- gluo M earthquake, and its focal depth is about 15 km; (4) the Moho depth trend and Bouguer gravity anomaly vari- ation indicates that the regional gravity field is strongly correlated with the Moho discontinuity.
基金This work is supported by the National Natural Science Foun-dation of China(42074105,41674096)Natural Science Foundation of Jiangsu Province(BK20131033)。
文摘The study of postseismic deformation is important for constraining the viscoelastic properties of the Earth and inverting the post-earthquake process.The levelling survey revealed that the area near Bei-chuan elevated 5.3 cm about two years after the M_(W) 7.9 Wenchuan earthquake(05/12/2008),during which the area underwent significant downward movement.The GPS horizontal displacements showed a non-monotonic variation after the Wenchuan earthquake.In this study,a 3-D viscoelastic finite element model is employed to simulate the coseismic and postseismic deformation of the Wenchuan earthquake.The numerical simulations show that the lateral heterogeneity across the Longmenshan fault plays an important role in the postseismic displacements.The results reveal that the coseismic defor-mation is not sensitive to the horizontal heterogeneity,but the postseismic deformation is sensitive to it.The postseismic deformation of the horizontally heterogeneous model is generally consistent with the observations of all geodetic surveys,such as GPS,InSAR and levelling,but not for the horizontally homogenous model.We also find that the non-monotonous variation of the postseismic deformation of the Wenchuan earthquake could be explained by a viscoelastic relaxation model with lateral heterogeneous medium across the Longmenshan fault.
基金the support from Science for Earthquake Resilience of the China Earthquake Administration(XH17022)the National Natural Science Foundation of China(Grant No.U1939204,No.41204014)+1 种基金the Scientific Research Fund of Institute of Seismology and Institute of Crustal Dynamics,China Earthquake Administration(Grant No.IS20146141)National Key Research and Development Plan(Grant No.2017YFC1500204).
文摘In this paper,we present an open python procedure with Jupyter notebook,for data extraction and vectorization of geophysical explo ration profile.Constrained by observation routes and traffic conditions,geophysical exploration profiles tend to bend curved roads for easy observation,however,it must be projected onto a straight line when data processing and analyzing.After projection,we don’t know the true position of the obtained crustal structure.Nonetheless,when the results used as an initial constraint condition for other geophysical inversion,such as gravity inversion,we need to know the true position of the data rather than the distance to the starting point.We solved this problem by profile vectorization and reprojection.The method can be used for extraction data of various geophysical exploration profiles,such as seismic reflection profiles,gravity profiles.
基金funded by The National Natural Science Foundation of China(No.41774015,41704135 and U1939204)National Key Research and Development Project of China(No.2018YFE0206100,2017YFC1500204)。
文摘Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia.In this paper,taking advantage of a unique network of gravity tidal stations all over the Chinese mainland,we compare the observed and modeled tidal loading effects on the basis of the most recent global ocean tide models.The results show that the average efficiencies of the ocean tidal loading correction for O_(1),K_(1),M_(2) are 77%,7 s3%and 59%,respectively.The loading correction efficiencies using recent ocean tidal models are better than the 40 years old Schwiderskis model at coastal stations,but relative worse at stations far from ocean.
基金funded by the National Natural Science Foundation of China(Grant No.:52076159).
文摘Cryogenic energy storage(CES)is a viable method for grid-scale electrical energy storage.Considering the high energy density and mature application of liquefied natural gas(LNG),we proposed an LNG cryogenic energy storage(LNGES)system.A steady-state process model of the LNGES system was established using Aspen HYSYS.The effects of the natural gas composition and key operating parameters such as the charging pressure,discharging pressure,throttling temperature,and liquid storage pressure on the system performance were investigated.A multi-parameter genetic algorithm model built using the MATLAB software was used to optimize the LNGES system to optimize the round-trip efficiency(RTE).Then,an exergy analysis of the optimal configuration was conducted.The results suggested that the LNGES system could achieve optimal RTE and exergy efficiency values of 60.14%and 71.64%,respectively.Exergy destruction mainly occurred during the compression,throttling,expansion,and heat exchange.The proposed LNGES system could be a promising candidate for the large-scale application of CES technology in power grids and gas networks.
基金the National Natural Science Foundation of China(Grant No:52076159).
文摘Cryogenic energy storage(CES)has garnered attention as a large-scale electric energy storage technology for the storage and regulation of intermittent renewable electric energy in power networks.Nitrogen and argon can be found in the air,whereas methane is the primary component of natural gas,an important clean energy resource.Most research on CES focuses on liquid air energy storage(LAES),with its typical round-trip efficiency(RTE)being approximately 50%(theoretical).This study aims to explore the feasibility of using different gases as working media in CES systems,and consequently,to achieve a high system efficiency by constructing four steady-state process models for the CES systems with air,nitrogen,argon,and methane as working media using Aspen HYSYS.A combined single-parameter analysis and multi-parameter global optimization method was used for system optimization.Further,a group of key independent variables were analysed carefully to determine their reasonable ranges to achieve the ideal system performance,that is,RTE and liquefaction ratio through a single-parameter analysis.Consequently,a multi-parameter genetic algorithm was adopted to globally optimize the CES systems with different working media,and the energy and exergy analyses were conducted for the CES systems under their optimal conditions.The results indicated the high cycle efficiency of methane and a low irreversible loss in the liquefaction cycle.Moreover,the Joule-Thomson valve inlet temperature and charging and discharging pressures considerably affected the system performance.However,exergy loss in the CES system occurred primarily in the compressor,turbine,and liquefaction processes.The maximum optimal RTE of 55.84%was achieved in the liquid methane energy storage(LMES)system.Therefore,the LMES system is expected to exhibit potential for application in the CES technology to realize the integration of natural gas pipelines with renewable power grids on a large scale.Moreover,the results of study have important theoretical significance for the innovation of the CES technology.
基金funded by the National Natural Science Foundation of China(Grant No.:52076159).
文摘Flexible gas power plants are subject to energy storage,peak regulations,and greenhouse gas emissions.This study proposes an integrated power generation system that combines liquid air energy storage(LAES),liquefied natural gas(LNG)cold energy utilization,gas power systems,and CO_(2) capture and storage(CCS)technologies,named the LAES-LNG-CCS system.The off-peak electricity can be stored in liquid air.During the peak period,air and gas turbines generate supplementary electricity.Both LNG chemical energy and cold energy were considered:the former was used for gas power plants,and the latter was used for LAES regasification and CCS processes.Based on the thermodynamic analysis,we evaluated the effects of the recovery pressure,CCS pressure,and combustion temperature on the system power consumption and efficiency.The results demonstrated that the system recovery pressure,CCS pressure,and combustion temperature had the greatest effects on system power generation.Round-trip efficiency(RTE)was significantly affected by combustion temperature.The largest exergy loss occurred in the gas power plant.The optimal system operating ranges of the system recovery pressure,CCS pressure,and combustion temperature were 6−10 MPa,0.53−0.8 MPa,and 1,503−1,773 K,where the RTEs and𝜂Ex,RS reached 55%−58.98%and 74.6%−76%,respectively.The proposed system can simultaneously achieve the synergistic functions of large-scale energy storage,multilevel energy utilization,peak regulation,and carbon emission reduction.It can also be widely used in advanced distributed energy storage applications in the future.