An artificial water curtain system is composed of a network of underground galleries and horizontal boreholes drilled from these galleries.Pre-grouting measures are introduced to keep the bedrock saturated all the tim...An artificial water curtain system is composed of a network of underground galleries and horizontal boreholes drilled from these galleries.Pre-grouting measures are introduced to keep the bedrock saturated all the time.This system is deployed over an artificial or natural underground cavern used for the storage of gas（or some other fluids） to prevent the gas from escaping through leakage paths in the rock mass.An experimental physical modeling system has been constructed to evaluate the performance of artificial water curtain systems under various conditions.These conditions include different spacings of caverns and cavern radii located below the natural groundwater level.The principles of the experiment,devices,design of the physical model,calculation of gas leakage,and evaluation of the critical gas pressure are presented in this paper.Experimental result shows that gas leakage is strongly affected by the spacing of water curtain boreholes,the critical gas pressure,and the number and proximity of storage caverns.The hydraulic connection between boreholes is observed to vary with depth or location,which suggests that the distribution of water-conducting joint sets along the boreholes is also variable.When designing the drainage system for a cavern,drainage holes should be orientated to maximize the frequency at which they encounter major joint sets and permeable intervals studying in order to maintain the seal on the cavern through water pressure.Our experimental results provide a significant contribution to the theoretical controls on water curtains,and they can be used to guide the design and construction of practical storage caverns.展开更多
The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been bu...The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been built in China since the 1970s, there is still a lack of experience for large-volume underground storage in complicated geological conditions. The current design concept of water curtain system and the technical instruction for system operation have limitations in maintaining the stability of surrounding rock mass during the construction of the main storage caverns, as well as the long-term stability. Although several large-scale underground oil storage projects are under construction at present in China, the design concepts and construction methods, especially for the water curtain system, are mainly based on the ideal porosity medium flow theory and the experiences gained from the similar projects overseas. The storage projects currently constructed in China have the specific features such as huge scale, large depth, multiple-level arrangement, high seepage pressure, complicated geological conditions, and high in situ stresses, which are the challenging issues for the stability of the storage caverns. Based on years’ experiences obtained from the first large-scale （millions of cubic meters） underground water-sealed oil storage project in China, some design and operation problems related to water curtain system during project construction are discussed. The drawbacks and merits of the water curtain system are also presented. As an example, the conventional concept of “filling joints with water” is widely used in many cases, as a basic concept for the design of the water curtain system, but it is immature. In this paper, the advantages and disadvantages of the conventional concept are pointed out, with respect to the long-term stability as well as the safety of construction of storage caverns. Finally, new concepts and principles for design and construction of the underground water-sealed oil storage caverns are proposed.展开更多
[Objectives]The purpose was to solve the problem that high temperature and high humidity will seriously affect the health and weight gain of pigs.[Methods]The fan-water curtain cooling system was popularized in large-...[Objectives]The purpose was to solve the problem that high temperature and high humidity will seriously affect the health and weight gain of pigs.[Methods]The fan-water curtain cooling system was popularized in large-scale pig farms.[Results]The pigs using the water curtain cooling system gained 1.5 kg from weaning to the day of slaughter.The feed-to-gain ratio was 2.43∶1,a year-on-year decrease of 0.05.The average weight gain per pig was about 5-10 kg.[Conclusions]The application of fan-water curtain cooling system in pig production can accelerate the growth rate of pigs,reduce the occurrence of diseases and improve the utilization of feed,eventually improving the productivity of pigs.展开更多
Water curtain systems(WCSs)are key components for the operation of underground oil storage caverns(UOSCs)and their optimization and design are important areas of research.Based on the time series monitoring of the fir...Water curtain systems(WCSs)are key components for the operation of underground oil storage caverns(UOSCs)and their optimization and design are important areas of research.Based on the time series monitoring of the first large-scale underground water-sealed storage cavern project in China,and on finite element analysis,this study explores the optimum design criteria for WCSs in water-sealed oil caverns.It shows that the optimal hole spacing of the WCS for this underground storage cavern is 10 m in order to ensure seal effectiveness.When the WCS is designed with a 10-m horizontal hole spacing and a water curtain pressure(WCP)of 80 kPa,a water curtain hole(WCH)has an influence radius of approximately 25 m.The smaller the vertical distance is between a WCH and the main cavern,the greater the water inflow into the main cavern.The vertical hydraulic gradient criterion can be satisfied when this distance is 25 m.It shows that the optimal WCP is 70 kPa,which meets sealing requirements.展开更多
Water sealing performance is important for underground water-sealed oil storage(UWSOS).The key issues concerning water sealing performance mainly include the permeability of fractured rock mass(FRM),water-sealed safet...Water sealing performance is important for underground water-sealed oil storage(UWSOS).The key issues concerning water sealing performance mainly include the permeability of fractured rock mass(FRM),water-sealed safety(WSS),water curtain performance,and prediction and control of water inflow.This paper reviews the progress of above four key issues on water sealing performances.First,the permeability of an FRM is the basis of water sealing performance,and several commonly used permeability test methods and spatial variation characteristics of permeability are outlined.Second,the current water sealing criteria are compared,and the evaluation methods of WSS are summarized.Third,the design parameters and efficiency evaluation of water curtain systems(WCSs)are introduced.The water inflow of oil storage caverns(OSCs)can reflect the water sealing effect,and the prediction methods and control measures of water inflow are also summarized.Finally,the advantages and disadvantages of the current research are discussed,and the potential research directions are pointed out,such as optimization of water sealing criteria and FRM model,quantitative evaluation of WCS efficiency,accurate prediction of water inflow,and improvement of grouting technology.展开更多
Aiming at the serious heat and cold loss of the building glass curtain wall in the field of amusement and tourism,and the need to meet the landscape requirements of the building facade,this paper put forward the idea ...Aiming at the serious heat and cold loss of the building glass curtain wall in the field of amusement and tourism,and the need to meet the landscape requirements of the building facade,this paper put forward the idea of integrating the shading and consumption reduction of glass curtain wall with the landscape requirements,that is,the water curtain was set outside the glass curtain wall to form a landscape energy-saving integrated water curtain wall system,while meeting the needs of landscape and shading.By establishing the numerical calculation model of the system,the corresponding relationship between the thickness of water film and the weakening of solar radiation intensity was revealed,as well as the influence of wind speed and wind direction on the nozzle exit angle and velocity selection;and the synergistic law of air flow rate and air temperature drop amplitude.The results showed that the water film thickness at 3-4 cm can reduce the solar radiation by 65%-80%.The temperature of the air layer between the water film and the curtain wall decreased as the air flow rate decreased,when the thickness of water film was 2 cm and the air velocity was 0.5-1.5 m/s,the air temperature dropped to 2.47-3.6°C.Finally,through the analysis of the actual project-ICE World&WATER Park,the system can reduce 66.8%of solar radiation,and reduce the air layer temperature by 3.9°C.展开更多
The principles of fine water mist explosion-extinguishing system was introduced. The defects of current systems were analyzed. The concept of a new water column cur-tain and the explosion-extinguishing mechanism were ...The principles of fine water mist explosion-extinguishing system was introduced. The defects of current systems were analyzed. The concept of a new water column cur-tain and the explosion-extinguishing mechanism were given. Using water column curtain to suppress methane explosion in experiment pipes was conducted. The photos were written with schlieren photograph system. The results of experiment show that the effect is perfect.展开更多
基金Supported by the National Natural Science Foundation of China (50779025,50539090)the Open Research Foundation of State Key Laboratory of Hydroscience and Engineering of Tsinghua University (200805331143)
文摘An artificial water curtain system is composed of a network of underground galleries and horizontal boreholes drilled from these galleries.Pre-grouting measures are introduced to keep the bedrock saturated all the time.This system is deployed over an artificial or natural underground cavern used for the storage of gas（or some other fluids） to prevent the gas from escaping through leakage paths in the rock mass.An experimental physical modeling system has been constructed to evaluate the performance of artificial water curtain systems under various conditions.These conditions include different spacings of caverns and cavern radii located below the natural groundwater level.The principles of the experiment,devices,design of the physical model,calculation of gas leakage,and evaluation of the critical gas pressure are presented in this paper.Experimental result shows that gas leakage is strongly affected by the spacing of water curtain boreholes,the critical gas pressure,and the number and proximity of storage caverns.The hydraulic connection between boreholes is observed to vary with depth or location,which suggests that the distribution of water-conducting joint sets along the boreholes is also variable.When designing the drainage system for a cavern,drainage holes should be orientated to maximize the frequency at which they encounter major joint sets and permeable intervals studying in order to maintain the seal on the cavern through water pressure.Our experimental results provide a significant contribution to the theoretical controls on water curtains,and they can be used to guide the design and construction of practical storage caverns.
文摘The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been built in China since the 1970s, there is still a lack of experience for large-volume underground storage in complicated geological conditions. The current design concept of water curtain system and the technical instruction for system operation have limitations in maintaining the stability of surrounding rock mass during the construction of the main storage caverns, as well as the long-term stability. Although several large-scale underground oil storage projects are under construction at present in China, the design concepts and construction methods, especially for the water curtain system, are mainly based on the ideal porosity medium flow theory and the experiences gained from the similar projects overseas. The storage projects currently constructed in China have the specific features such as huge scale, large depth, multiple-level arrangement, high seepage pressure, complicated geological conditions, and high in situ stresses, which are the challenging issues for the stability of the storage caverns. Based on years’ experiences obtained from the first large-scale （millions of cubic meters） underground water-sealed oil storage project in China, some design and operation problems related to water curtain system during project construction are discussed. The drawbacks and merits of the water curtain system are also presented. As an example, the conventional concept of “filling joints with water” is widely used in many cases, as a basic concept for the design of the water curtain system, but it is immature. In this paper, the advantages and disadvantages of the conventional concept are pointed out, with respect to the long-term stability as well as the safety of construction of storage caverns. Finally, new concepts and principles for design and construction of the underground water-sealed oil storage caverns are proposed.
文摘[Objectives]The purpose was to solve the problem that high temperature and high humidity will seriously affect the health and weight gain of pigs.[Methods]The fan-water curtain cooling system was popularized in large-scale pig farms.[Results]The pigs using the water curtain cooling system gained 1.5 kg from weaning to the day of slaughter.The feed-to-gain ratio was 2.43∶1,a year-on-year decrease of 0.05.The average weight gain per pig was about 5-10 kg.[Conclusions]The application of fan-water curtain cooling system in pig production can accelerate the growth rate of pigs,reduce the occurrence of diseases and improve the utilization of feed,eventually improving the productivity of pigs.
基金Project supported by the National Natural Science Foundation of China (Nos. 41877239, 51379112, 51422904, 40902084, and 41772298)the Fundamental Research Funds for the Central Universities (No. 2018JC044)the Natural Science Foundation of Shandong Province (No. JQ201513),China。
文摘Water curtain systems(WCSs)are key components for the operation of underground oil storage caverns(UOSCs)and their optimization and design are important areas of research.Based on the time series monitoring of the first large-scale underground water-sealed storage cavern project in China,and on finite element analysis,this study explores the optimum design criteria for WCSs in water-sealed oil caverns.It shows that the optimal hole spacing of the WCS for this underground storage cavern is 10 m in order to ensure seal effectiveness.When the WCS is designed with a 10-m horizontal hole spacing and a water curtain pressure(WCP)of 80 kPa,a water curtain hole(WCH)has an influence radius of approximately 25 m.The smaller the vertical distance is between a WCH and the main cavern,the greater the water inflow into the main cavern.The vertical hydraulic gradient criterion can be satisfied when this distance is 25 m.It shows that the optimal WCP is 70 kPa,which meets sealing requirements.
基金supported by the National Natural Science Foundation of China(Grant Nos.41972300,41572301,and 42107201).
文摘Water sealing performance is important for underground water-sealed oil storage(UWSOS).The key issues concerning water sealing performance mainly include the permeability of fractured rock mass(FRM),water-sealed safety(WSS),water curtain performance,and prediction and control of water inflow.This paper reviews the progress of above four key issues on water sealing performances.First,the permeability of an FRM is the basis of water sealing performance,and several commonly used permeability test methods and spatial variation characteristics of permeability are outlined.Second,the current water sealing criteria are compared,and the evaluation methods of WSS are summarized.Third,the design parameters and efficiency evaluation of water curtain systems(WCSs)are introduced.The water inflow of oil storage caverns(OSCs)can reflect the water sealing effect,and the prediction methods and control measures of water inflow are also summarized.Finally,the advantages and disadvantages of the current research are discussed,and the potential research directions are pointed out,such as optimization of water sealing criteria and FRM model,quantitative evaluation of WCS efficiency,accurate prediction of water inflow,and improvement of grouting technology.
基金project Xiangjiang Happy City — Ice World & Water Park, which is constructed by Ltd of China Construction Fifth Engineering
文摘Aiming at the serious heat and cold loss of the building glass curtain wall in the field of amusement and tourism,and the need to meet the landscape requirements of the building facade,this paper put forward the idea of integrating the shading and consumption reduction of glass curtain wall with the landscape requirements,that is,the water curtain was set outside the glass curtain wall to form a landscape energy-saving integrated water curtain wall system,while meeting the needs of landscape and shading.By establishing the numerical calculation model of the system,the corresponding relationship between the thickness of water film and the weakening of solar radiation intensity was revealed,as well as the influence of wind speed and wind direction on the nozzle exit angle and velocity selection;and the synergistic law of air flow rate and air temperature drop amplitude.The results showed that the water film thickness at 3-4 cm can reduce the solar radiation by 65%-80%.The temperature of the air layer between the water film and the curtain wall decreased as the air flow rate decreased,when the thickness of water film was 2 cm and the air velocity was 0.5-1.5 m/s,the air temperature dropped to 2.47-3.6°C.Finally,through the analysis of the actual project-ICE World&WATER Park,the system can reduce 66.8%of solar radiation,and reduce the air layer temperature by 3.9°C.
基金Supported by National Nature Science Foundation of China(59925411)
文摘The principles of fine water mist explosion-extinguishing system was introduced. The defects of current systems were analyzed. The concept of a new water column cur-tain and the explosion-extinguishing mechanism were given. Using water column curtain to suppress methane explosion in experiment pipes was conducted. The photos were written with schlieren photograph system. The results of experiment show that the effect is perfect.
