Notably, the Nigeria Liquefied Natural Gas (NLNG) project is the pioneer Liquefied Natural Gas (LNG) plant in Nigeria, aimed at both the diversification of the petroleum industry and utilization of the vastly flared n...Notably, the Nigeria Liquefied Natural Gas (NLNG) project is the pioneer Liquefied Natural Gas (LNG) plant in Nigeria, aimed at both the diversification of the petroleum industry and utilization of the vastly flared natural gas resources of the nation. However, large scale energy projects have been known to generate both positive and/or negative impacts. Environmental Management Plans (EMP) have often been the compendium of information on approved mitigations, which normally include activities that could maximize the benefits of the host communities, and it’s not unusual for the Community Development and Corporate Social Responsibility (CDCSR) department of such an organization to be saddled with these contributions. But the activities of Nigeria LNG Ltd.’s CSR department have often been the source of criticism, as well as aspiration for improvement by host communities and other stake holders. This article thus aims to present a comprehensive compendium of NLNG’s CDCSR activities, up to the year 2010, and also highlight the level of satisfaction of the immediate and distant host communities against the level of performance of other donors in the area. Also the arrays of negative socio-economic consequences of the Nigeria LNG Ltd.’s activities were identified based on community perception. The results generally showed that comparatively, NLNG project has made more innovative positive socio-economic and health contributions to its areas of operation than the three tiers of government and other donors (including SPDC and Mobil Producing Nigeria). Surprisingly, agitations against Nigeria LNG Ltd.’s activities have not overshadowed its community development provisions, which have been of major assistance in several communities. There is however a dire need to review several aspects of Nigeria LNG Ltd.’s CDCSR activities, especially in the fulfilment of documented promises, as well as in project conception and community participation, for better completed projects acceptance by indigenous host communities. Conflict management strategies also need to be improved, while the dissatisfaction over benefits in New Finima needs to be urgently addressed.展开更多
Two schemes(scheme Ⅰ and scheme Ⅱ)for designing a district cooling system(DCS)utilizing cold energy of liquefied natural gas(LNG)are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice i...Two schemes(scheme Ⅰ and scheme Ⅱ)for designing a district cooling system(DCS)utilizing cold energy of liquefied natural gas(LNG)are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.展开更多
A large portion of world's natural gas reserves are "stranded" resources, the drive to monetize these resources leads to the development of gas-to-liquids (GTL) and liquefied natural gas (LNG) technologies. LNG...A large portion of world's natural gas reserves are "stranded" resources, the drive to monetize these resources leads to the development of gas-to-liquids (GTL) and liquefied natural gas (LNG) technologies. LNG has the advantage of having been developed for the past 40 years and having an excellent safety record. GTL on the other hand is another option with substantial benefits, but its development stage and commercial viability are far behind LNG. This paper presents a techno-economic comparison of GTL with LNG, including technical development, plant efficiency, market potential for the products, and capital cost for the infrastructure. The aim is to give an overall view on both LNG and GTL and provide a perspective on the profitability of these two technologies.展开更多
The production and consumption of natural gas in China has been developing rapidly in recent years.It is expected that the annual growth rate of the demand for natural gas will reach 12% in the next 15 years,and the g...The production and consumption of natural gas in China has been developing rapidly in recent years.It is expected that the annual growth rate of the demand for natural gas will reach 12% in the next 15 years,and the gas consumption in the primary energy will increase from 0.3% to 10% or more by 2020.However,since the supply of natural gas cannot satisfy the requirements,China has begun to build liquefied natural gas(LNG)terminals in the coastal regions such as Guangdong and Fujian,and solve this problem by importing LNG from foreign countries.LNG needs to be transported by LNG ships from abroad.With the rapid growth of global gas production,the volume of LNG trade also increases,and the interregional production increased from 0.3% in 1970 to 26.2% in 2004.So,we need LNG ships more than before.This article puts forward the distribution of LNG ships and the speculation of the future of LNG transportation based on the studies on foreign LNG production,the LNG trade,the building of LNG ships,the LNG transportation,the chain model of LNG distribution,etc.展开更多
Due to the flammability and explosive nature of liquefied natural gas(LNG),an extremely strict process is followed for the transporta-tion of LNG carriers in China.Particularly,no LNG carriers are operating in inland ...Due to the flammability and explosive nature of liquefied natural gas(LNG),an extremely strict process is followed for the transporta-tion of LNG carriers in China.Particularly,no LNG carriers are operating in inland rivers within the country.Therefore,to ensure the future navigation safety of LNG carriers entering the Yangtze River,the risk sources of LNG carriers’navigation safety must be identi-fied and evaluated.Based on the Delphi and expert experience method,this paper analyses and discusses the navigation risk factors of LNG carriers in the lower reaches of the Yangtze River from four aspects(human,ship,environment and management),identifies 12 risk indicators affecting the navigation of LNG carriers and establishes a risk evaluation index system.Further,an entropy weight fuzzy model is utilized to reduce the influence of subjective judgement on the index weight as well as to conduct a segmented and overall evaluation of LNG navigation risks in the Baimaosha Channel.Finally,the cloud model is applied to validate the consistent feasibility of the entropy weight fuzzy model.The research results indicate that the method provides effective technical support for further study on the navigation security of LNG carriers in inland rivers.展开更多
Propulsion of liquefied natural gas (LNG) ships is undergoing significant change. The traditional steam plant is losing favor because of its low cycle efficiency. Medium-speed diesel-electric and slow-speed diesel-mec...Propulsion of liquefied natural gas (LNG) ships is undergoing significant change. The traditional steam plant is losing favor because of its low cycle efficiency. Medium-speed diesel-electric and slow-speed diesel-mechanical drive ships are in service, and more are being built. Another attractive alternative is combined gas and steam turbine (COGAS) drive. This approach offers significant advantages over steam and diesel propulsion. This paper presents the case for the COGAS cycle.展开更多
The paper introduces gas to liquids (GTL) as a monetising option from a technology, marketing and project perspective. GTL is complementary to LNG and pipelines. At the same time, using natural gas as a source for fue...The paper introduces gas to liquids (GTL) as a monetising option from a technology, marketing and project perspective. GTL is complementary to LNG and pipelines. At the same time, using natural gas as a source for fuels in the form of GTL helps countries around the world to diversify their energy supplies. Furthermore, gas-based products are inherently cleaner than oil products. Shell's proprietary GTL technology or SMDS (Shell Middle Distillates Synthesis), is discussed in some detail. The paper also covers the challenges for successful implementation of GTL projects and why Shell is well positioned to take a lead in the industry on the basis of its long standing and broad experience in GTL research, plant operations, marketing and excellent track record in mega projects in the last thirty years. Shell's commitment to GTL is best demonstrated by the recent signing of a Heads of Agreement with Qatar Petroleum for the construction of the world's largest GTL plant. A key success factor is Shell's experience with marketing quantities of high quality GTL products from its 12,500 barrels per day plant at Bintulu, Malaysia since 1993. Further marketing opportunities will arise when new GTL capacity comes on-stream in the middle east when more quantities will become available to bulk users. Amongst the most interesting market will be automotive transportation, where clean GTL fuels can be positioned as an 'alternative fuel beyond oil' providing energy security to host countries. Shell is actively engaging with a number of regulators, automotive companies and governments worldwide including China, to demonstrate the performance of GTL and its cost effectiveness in reducing local emissions. An added benefit is that GTL can use existing infrastructure and requires no investment. Finally, the paper briefly discusses the coal to liquids (CTL) process as an alternative route to produce high quality GTL products and the key issues relating to the process.展开更多
This paper describes the characteristics of liquefied natural gas (LNG) carriers briefly. The LNG carrier includes power plant selection, vapor treatment, liquid cargo tank type, etc. Two parameters fuel substitutio...This paper describes the characteristics of liquefied natural gas (LNG) carriers briefly. The LNG carrier includes power plant selection, vapor treatment, liquid cargo tank type, etc. Two parameters fuel substitution rate and recovery of boil of gas (BOG) volume to energy efficiency design index (EEDI) formula are added, and EEDI formula of LNG carriers is established based on ship EEDI formula. Then, based on steam turbine propulsion device of LNG carriers, mathematical models of LNG carriers' reference line value are established in this paper. By verification, the EEDI formula of LNG carriers described in this paper can provide a reference for LNG carrier EEDI calculation and green shipbuilding.展开更多
This article is focused on technical and economic evaluation of more than 6-years experiences of operating the Waste Heat Recovery technology—the manner and system of flue gas processing generated in the combustion p...This article is focused on technical and economic evaluation of more than 6-years experiences of operating the Waste Heat Recovery technology—the manner and system of flue gas processing generated in the combustion process in heat & power plants, cogeneration units, etc., which burn the gaseous fuel, primarily natural gas, or methane, biogas, geothermal gas, or other gaseous mixtures containing hydrogen. The solution proposes a more effective and non-traditional use of gaseous fuel for heating, the flue gases of which are processed in order to extract additional utilisable heat, with potential elimination of CO2 from them. Deploying of the heating plant in an island regime (OFF-GRID) enables definition of the benefits brought by the 3 years of operational experience and presents visions for the future offering the possibility to utilise the support energy services at the municipal as well as regional level.展开更多
With the global energy transformation the international liquefied natural gas(LNG) market is undergoing profound changes. Due to world economic development, industrial restructuring, natural gas and alternative energy...With the global energy transformation the international liquefied natural gas(LNG) market is undergoing profound changes. Due to world economic development, industrial restructuring, natural gas and alternative energy competition as well as other factors, global LNG supply and demand, LNG market structure and LNG prices will start to show new trends shortly. Hence, China, a major natural gas producer and an important LNG importer in the world,will face plenty of new opportunities and challenges in LNG imports. In response, we must take appropriate measures on industrial policies and regulations, prices and markets, etc.展开更多
With the global energy transformation the international liquefied natural gas(LNG)market is undergoing profound changes.Due to world economic development,industrial restructuring,natural gas and alternative energy com...With the global energy transformation the international liquefied natural gas(LNG)market is undergoing profound changes.Due to world economic development,industrial restructuring,natural gas and alternative energy competition as well as other factors,global LNG supply and demand,LNG market structure and LNG prices will start to show new trends shortly.Hence,China,a major natural gas producer and an important LNG importer in the world,will face plenty of new opportunities and challenges in LNG imports.In response,we must take appropriate measures on industrial policies and regulations,prices and markets,etc.展开更多
Liquefied natural gas (LNG), an increasingly widely applied clean fuel, releases a large number of cold energy in its regasification process. In the present paper, the existing power generation cycles utilizing LNG ...Liquefied natural gas (LNG), an increasingly widely applied clean fuel, releases a large number of cold energy in its regasification process. In the present paper, the existing power generation cycles utilizing LNG cold energy are introduced and summarized. The direction of cycle improvement can be divided into the key factors affecting basic power generation cycles and the structural enhancement of cycles utilizing LNG cold energy. The former includes the effects of LNG-side parameters, working fluids, and inlet and outlet thermodynamic parameters of equipment, while the latter is based on Rankine cycle, Brayton cycle, Kalina cycle and their compound cycles. In the present paper, the diversities of cryogenic power generation cycles utilizing LNG cold energy are discussed and analyzed. It is pointed out that further researches should focus on the selection and component matching of organic mixed working fluids and the combination of process simulation and experi- mental investigation, etc.展开更多
The insulation of membrane type liquefied natunal gas (LNG) carrier is composed of plywood boxes filled with perlite. Within the service period, considering of the effects of load conditions, such as sloshing, wave ...The insulation of membrane type liquefied natunal gas (LNG) carrier is composed of plywood boxes filled with perlite. Within the service period, considering of the effects of load conditions, such as sloshing, wave load, it is possible to have some damage of the plywood box, leakage of perlite, and failure of the insulation box. LNG carrier without whole protection of effective insulation is dangerous. Hull structure is extremely fragile when exposed to ultra-low temperature. In order to solve these problems, firstly a study on insulation boxes' character and work condition is carried out and some presuppositions of partial disabled insulation are put forward. Secondly the thermal system of LNG carrier is analyzed to find out an effective way to simulate the thermal action of close air between outer and inner hull. Then a calculation about temperature field and thermal stress is done by MSC/PATRAN&NASTRAN. At the end it is concluded that LNG carrier with incomplete insulation is dangerous and needs to be avoided.展开更多
Liquid sloshing phenomena in No.2 tank of 140 km 3 liquefied natural gas (LNG) carriers have been studied numerically and experimentally.The scale of the model tank was selected as 1/55.9.Roll and pitch motions were t...Liquid sloshing phenomena in No.2 tank of 140 km 3 liquefied natural gas (LNG) carriers have been studied numerically and experimentally.The scale of the model tank was selected as 1/55.9.Roll and pitch motions were tested.For measuring impact pressures,seventeen pressure sensors were installed on the tank model.A large number of excitation frequencies and filling heights were investigated.The experimental results showed that when the frequency of tank motion is close to the natural frequency of fluid inside the tank,large impact pressures may be caused.Resonance frequencies and maximum impact pressures of different filling height were presented.Among all the experimental situations,the maximum impact pressure always occurs at the place near 70% height of tank where should be especially concerned.A computational fluid dynamics (CFD) model was developed to simulate the sloshing in the tank.The model was based on the Reynolds-averaged Navier-Stokes (RANS) equations,with a standard κ-ε turbulence model.The volume of fluid (VOF) method was used to predict free surface elevations.Dynamic mesh technique was used to update the volume mesh.Computations for pressure time histories and peak pressures were compared to experimental results.Good agreement was observed.展开更多
文摘Notably, the Nigeria Liquefied Natural Gas (NLNG) project is the pioneer Liquefied Natural Gas (LNG) plant in Nigeria, aimed at both the diversification of the petroleum industry and utilization of the vastly flared natural gas resources of the nation. However, large scale energy projects have been known to generate both positive and/or negative impacts. Environmental Management Plans (EMP) have often been the compendium of information on approved mitigations, which normally include activities that could maximize the benefits of the host communities, and it’s not unusual for the Community Development and Corporate Social Responsibility (CDCSR) department of such an organization to be saddled with these contributions. But the activities of Nigeria LNG Ltd.’s CSR department have often been the source of criticism, as well as aspiration for improvement by host communities and other stake holders. This article thus aims to present a comprehensive compendium of NLNG’s CDCSR activities, up to the year 2010, and also highlight the level of satisfaction of the immediate and distant host communities against the level of performance of other donors in the area. Also the arrays of negative socio-economic consequences of the Nigeria LNG Ltd.’s activities were identified based on community perception. The results generally showed that comparatively, NLNG project has made more innovative positive socio-economic and health contributions to its areas of operation than the three tiers of government and other donors (including SPDC and Mobil Producing Nigeria). Surprisingly, agitations against Nigeria LNG Ltd.’s activities have not overshadowed its community development provisions, which have been of major assistance in several communities. There is however a dire need to review several aspects of Nigeria LNG Ltd.’s CDCSR activities, especially in the fulfilment of documented promises, as well as in project conception and community participation, for better completed projects acceptance by indigenous host communities. Conflict management strategies also need to be improved, while the dissatisfaction over benefits in New Finima needs to be urgently addressed.
文摘Two schemes(scheme Ⅰ and scheme Ⅱ)for designing a district cooling system(DCS)utilizing cold energy of liquefied natural gas(LNG)are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.
文摘A large portion of world's natural gas reserves are "stranded" resources, the drive to monetize these resources leads to the development of gas-to-liquids (GTL) and liquefied natural gas (LNG) technologies. LNG has the advantage of having been developed for the past 40 years and having an excellent safety record. GTL on the other hand is another option with substantial benefits, but its development stage and commercial viability are far behind LNG. This paper presents a techno-economic comparison of GTL with LNG, including technical development, plant efficiency, market potential for the products, and capital cost for the infrastructure. The aim is to give an overall view on both LNG and GTL and provide a perspective on the profitability of these two technologies.
基金Under the auspices of the National Natural Science Foundation of China(No.40671052)
文摘The production and consumption of natural gas in China has been developing rapidly in recent years.It is expected that the annual growth rate of the demand for natural gas will reach 12% in the next 15 years,and the gas consumption in the primary energy will increase from 0.3% to 10% or more by 2020.However,since the supply of natural gas cannot satisfy the requirements,China has begun to build liquefied natural gas(LNG)terminals in the coastal regions such as Guangdong and Fujian,and solve this problem by importing LNG from foreign countries.LNG needs to be transported by LNG ships from abroad.With the rapid growth of global gas production,the volume of LNG trade also increases,and the interregional production increased from 0.3% in 1970 to 26.2% in 2004.So,we need LNG ships more than before.This article puts forward the distribution of LNG ships and the speculation of the future of LNG transportation based on the studies on foreign LNG production,the LNG trade,the building of LNG ships,the LNG transportation,the chain model of LNG distribution,etc.
基金sponsor from the National Natural Science Foundation of China(NSFC)(Grant No.51809207).
文摘Due to the flammability and explosive nature of liquefied natural gas(LNG),an extremely strict process is followed for the transporta-tion of LNG carriers in China.Particularly,no LNG carriers are operating in inland rivers within the country.Therefore,to ensure the future navigation safety of LNG carriers entering the Yangtze River,the risk sources of LNG carriers’navigation safety must be identi-fied and evaluated.Based on the Delphi and expert experience method,this paper analyses and discusses the navigation risk factors of LNG carriers in the lower reaches of the Yangtze River from four aspects(human,ship,environment and management),identifies 12 risk indicators affecting the navigation of LNG carriers and establishes a risk evaluation index system.Further,an entropy weight fuzzy model is utilized to reduce the influence of subjective judgement on the index weight as well as to conduct a segmented and overall evaluation of LNG navigation risks in the Baimaosha Channel.Finally,the cloud model is applied to validate the consistent feasibility of the entropy weight fuzzy model.The research results indicate that the method provides effective technical support for further study on the navigation security of LNG carriers in inland rivers.
文摘Propulsion of liquefied natural gas (LNG) ships is undergoing significant change. The traditional steam plant is losing favor because of its low cycle efficiency. Medium-speed diesel-electric and slow-speed diesel-mechanical drive ships are in service, and more are being built. Another attractive alternative is combined gas and steam turbine (COGAS) drive. This approach offers significant advantages over steam and diesel propulsion. This paper presents the case for the COGAS cycle.
文摘The paper introduces gas to liquids (GTL) as a monetising option from a technology, marketing and project perspective. GTL is complementary to LNG and pipelines. At the same time, using natural gas as a source for fuels in the form of GTL helps countries around the world to diversify their energy supplies. Furthermore, gas-based products are inherently cleaner than oil products. Shell's proprietary GTL technology or SMDS (Shell Middle Distillates Synthesis), is discussed in some detail. The paper also covers the challenges for successful implementation of GTL projects and why Shell is well positioned to take a lead in the industry on the basis of its long standing and broad experience in GTL research, plant operations, marketing and excellent track record in mega projects in the last thirty years. Shell's commitment to GTL is best demonstrated by the recent signing of a Heads of Agreement with Qatar Petroleum for the construction of the world's largest GTL plant. A key success factor is Shell's experience with marketing quantities of high quality GTL products from its 12,500 barrels per day plant at Bintulu, Malaysia since 1993. Further marketing opportunities will arise when new GTL capacity comes on-stream in the middle east when more quantities will become available to bulk users. Amongst the most interesting market will be automotive transportation, where clean GTL fuels can be positioned as an 'alternative fuel beyond oil' providing energy security to host countries. Shell is actively engaging with a number of regulators, automotive companies and governments worldwide including China, to demonstrate the performance of GTL and its cost effectiveness in reducing local emissions. An added benefit is that GTL can use existing infrastructure and requires no investment. Finally, the paper briefly discusses the coal to liquids (CTL) process as an alternative route to produce high quality GTL products and the key issues relating to the process.
基金Foundation item: Supported by the National Special Fund for Agro-scientific Research in the Public Interest (No.201003024), and the National Natural Science Foundation of China (No.51409042 No. 51209034).
文摘This paper describes the characteristics of liquefied natural gas (LNG) carriers briefly. The LNG carrier includes power plant selection, vapor treatment, liquid cargo tank type, etc. Two parameters fuel substitution rate and recovery of boil of gas (BOG) volume to energy efficiency design index (EEDI) formula are added, and EEDI formula of LNG carriers is established based on ship EEDI formula. Then, based on steam turbine propulsion device of LNG carriers, mathematical models of LNG carriers' reference line value are established in this paper. By verification, the EEDI formula of LNG carriers described in this paper can provide a reference for LNG carrier EEDI calculation and green shipbuilding.
文摘This article is focused on technical and economic evaluation of more than 6-years experiences of operating the Waste Heat Recovery technology—the manner and system of flue gas processing generated in the combustion process in heat & power plants, cogeneration units, etc., which burn the gaseous fuel, primarily natural gas, or methane, biogas, geothermal gas, or other gaseous mixtures containing hydrogen. The solution proposes a more effective and non-traditional use of gaseous fuel for heating, the flue gases of which are processed in order to extract additional utilisable heat, with potential elimination of CO2 from them. Deploying of the heating plant in an island regime (OFF-GRID) enables definition of the benefits brought by the 3 years of operational experience and presents visions for the future offering the possibility to utilise the support energy services at the municipal as well as regional level.
文摘With the global energy transformation the international liquefied natural gas(LNG) market is undergoing profound changes. Due to world economic development, industrial restructuring, natural gas and alternative energy competition as well as other factors, global LNG supply and demand, LNG market structure and LNG prices will start to show new trends shortly. Hence, China, a major natural gas producer and an important LNG importer in the world,will face plenty of new opportunities and challenges in LNG imports. In response, we must take appropriate measures on industrial policies and regulations, prices and markets, etc.
文摘With the global energy transformation the international liquefied natural gas(LNG)market is undergoing profound changes.Due to world economic development,industrial restructuring,natural gas and alternative energy competition as well as other factors,global LNG supply and demand,LNG market structure and LNG prices will start to show new trends shortly.Hence,China,a major natural gas producer and an important LNG importer in the world,will face plenty of new opportunities and challenges in LNG imports.In response,we must take appropriate measures on industrial policies and regulations,prices and markets,etc.
文摘Liquefied natural gas (LNG), an increasingly widely applied clean fuel, releases a large number of cold energy in its regasification process. In the present paper, the existing power generation cycles utilizing LNG cold energy are introduced and summarized. The direction of cycle improvement can be divided into the key factors affecting basic power generation cycles and the structural enhancement of cycles utilizing LNG cold energy. The former includes the effects of LNG-side parameters, working fluids, and inlet and outlet thermodynamic parameters of equipment, while the latter is based on Rankine cycle, Brayton cycle, Kalina cycle and their compound cycles. In the present paper, the diversities of cryogenic power generation cycles utilizing LNG cold energy are discussed and analyzed. It is pointed out that further researches should focus on the selection and component matching of organic mixed working fluids and the combination of process simulation and experi- mental investigation, etc.
文摘The insulation of membrane type liquefied natunal gas (LNG) carrier is composed of plywood boxes filled with perlite. Within the service period, considering of the effects of load conditions, such as sloshing, wave load, it is possible to have some damage of the plywood box, leakage of perlite, and failure of the insulation box. LNG carrier without whole protection of effective insulation is dangerous. Hull structure is extremely fragile when exposed to ultra-low temperature. In order to solve these problems, firstly a study on insulation boxes' character and work condition is carried out and some presuppositions of partial disabled insulation are put forward. Secondly the thermal system of LNG carrier is analyzed to find out an effective way to simulate the thermal action of close air between outer and inner hull. Then a calculation about temperature field and thermal stress is done by MSC/PATRAN&NASTRAN. At the end it is concluded that LNG carrier with incomplete insulation is dangerous and needs to be avoided.
文摘Liquid sloshing phenomena in No.2 tank of 140 km 3 liquefied natural gas (LNG) carriers have been studied numerically and experimentally.The scale of the model tank was selected as 1/55.9.Roll and pitch motions were tested.For measuring impact pressures,seventeen pressure sensors were installed on the tank model.A large number of excitation frequencies and filling heights were investigated.The experimental results showed that when the frequency of tank motion is close to the natural frequency of fluid inside the tank,large impact pressures may be caused.Resonance frequencies and maximum impact pressures of different filling height were presented.Among all the experimental situations,the maximum impact pressure always occurs at the place near 70% height of tank where should be especially concerned.A computational fluid dynamics (CFD) model was developed to simulate the sloshing in the tank.The model was based on the Reynolds-averaged Navier-Stokes (RANS) equations,with a standard κ-ε turbulence model.The volume of fluid (VOF) method was used to predict free surface elevations.Dynamic mesh technique was used to update the volume mesh.Computations for pressure time histories and peak pressures were compared to experimental results.Good agreement was observed.