Cold rolling circulating water station mainly supplies circulating cooling water for each unit in the cold rolling plant. The actual operation condition of circulating water pump deviates from the design, and the wate...Cold rolling circulating water station mainly supplies circulating cooling water for each unit in the cold rolling plant. The actual operation condition of circulating water pump deviates from the design, and the water pump runs away from the high efficiency zone. The existing problems in operation are analyzed, and corresponding measures are taken, which greatly reduces the energy consumption of the pumping station and achieves good results.展开更多
Since the treatment of circulating water will directly affect the discharge of chemical enterprises, the treatment of circulating water is an important link in the development of chemical enterprises, and the cooling ...Since the treatment of circulating water will directly affect the discharge of chemical enterprises, the treatment of circulating water is an important link in the development of chemical enterprises, and the cooling tower is the decisive factor to determine the temperature of circulating water. Therefore, it is necessary to analyze the problems existing in the cooling tower, and put forward corresponding countermeasures for the problems existing in the operation of circulating water cooling tower, so as to explore a reasonable solution.展开更多
Fouling caused by excess metal ions in hard water can negatively impact the performance of the circulating cooling water system(CCWS)by depositing ions on the heat exchanger's surface.Currently,the operation optim...Fouling caused by excess metal ions in hard water can negatively impact the performance of the circulating cooling water system(CCWS)by depositing ions on the heat exchanger's surface.Currently,the operation optimization of CCWS often prioritizes short-term flow velocity optimization for minimizing power consumption,without considering fouling.However,low flow velocity promotes fouling.Therefore,it's crucial to balance fouling and energy/water conservation for optimal CCWS long-term operation.This study proposes a mixed-integer nonlinear programming(MINLP)model to achieve this goal.The model considers fouling in the pipeline,dynamic concentration cycle,and variable frequency drive to optimize the synergy between heat transfer,pressure drop,and fouling.By optimizing the concentration cycle of the CCWS,water conservation and fouling control can be achieved.The model can obtain the optimal operating parameters for different operation intervals,including the number of pumps,frequency,and valve local resistance coefficient.Sensitivity experiments on cycle and environmental temperature reveal that as the cycle increases,the marginal benefits of energy/water conservation decrease.In periods with minimal impact on fouling rate,energy/water conservation can be achieved by increasing the cycle while maintaining a low fouling rate.Overall,the proposed model has significant energy/water saving effects and can comprehensively optimize the CCWS through its incorporation of fouling and cycle optimization.展开更多
Recent research on deterministic methods for circulating cooling water systems optimization has been well developed. However, the actual operating conditions of the system are mostly variable, so the system obtained u...Recent research on deterministic methods for circulating cooling water systems optimization has been well developed. However, the actual operating conditions of the system are mostly variable, so the system obtained under deterministic conditions may not be stable and economical. This paper studies the optimization of circulating cooling water systems under uncertain circumstance. To improve the reliability of the system and reduce the water and energy consumption, the influence of different uncertain parameters is taken into consideration. The chance constrained programming method is used to build a model under uncertain conditions, where the confidence level indicates the degree of constraint violation. Probability distribution functions are used to describe the form of uncertain parameters. The objective is to minimize the total cost and obtain the optimal cooling network configuration simultaneously.An algorithm based on Monte Carlo method is proposed, and GAMS software is used to solve the mixed integer nonlinear programming model. A case is optimized to verify the validity of the model. Compared with the deterministic optimization method, the results show that when considering the different types of uncertain parameters, a system with better economy and reliability can be obtained(total cost can be reduced at least 2%).展开更多
Mesoporous SiO_2 microspheres were synthesized using the sol-gel method and were characterized by TEM, FT-IR and BET techniques. The diameter of the microspheres is about 100—150 nm, and the average mesopore diameter...Mesoporous SiO_2 microspheres were synthesized using the sol-gel method and were characterized by TEM, FT-IR and BET techniques. The diameter of the microspheres is about 100—150 nm, and the average mesopore diameter is 2.55 nm, while the specific surface area is 1 088.9 m2/g. Mesoporous SiO_2 microspheres adsorb glutaraldehyde and immobilize laccase by means of the aldehyde group in glutaral which can react with the amidogen of laccase. The immobilization conditions were optimized at a glutaraldehyde concentration of 0.75%, a crosslinking time of 8 h, a laccase concentration of 0.04 L/L and an immobilization time of 10 h. When diesel leakage concentration was 80 mg/L, the highest corrosion inhibition efficiency of immobilized laccase reached 49.23%, which was slightly lower than the corrosion inhibition efficiency of free laccase(59%). The diesel degradation ratio could reach up to 45%. It has been proved that the immobilized laccase could degrade diesel to inhibit corrosion.展开更多
As intelligent sensors for marine applications rapidly advance,there is a growing emphasis on developing efficient,low-cost,and sustainable power sources to enhance their performance.With the continuous development of...As intelligent sensors for marine applications rapidly advance,there is a growing emphasis on developing efficient,low-cost,and sustainable power sources to enhance their performance.With the continuous development of triboelectric nanogenerators(TENGs),known for their simple structure and versatile operational modes,these devices exhibit promising technological potential and have garnered extensive attention from a broad spectrum of researchers.The single-electrode mode of TENGs presents an effective means to harness eco-friendly energy sourced from flowing water.In this study,the factors affecting the output performance were investigated using different structures of single-electrode solid-liquid TENGs placed in a circulating water tank.In addition,the solid‒liquid contact process was numerically simulated using the COMSOL Multiphysics software,and significant potential energy changes were obtained for the solid‒liquid contact and liquid flow processes.Finally,the energy generated is collected and converted to power several light-emitting diodes,demonstrating that solid‒liquid TENGs can generate effective electrical power in a flowing water environment.Through several experimental investigations,we finally determined that the flow rate of the liquid,the thickness of the friction electrode material,and the contact area have the most significant effect on the output efficiency of TENGs in the form of flowing water,which provides a guide for improving their performance in the future.展开更多
In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbul...In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbulence models with hydraulic performance experiment, SST k-co model was confirmed to study the rational determination of sampling frequency and time better. The Fast Fourier Transform （FFT） technology was then adopted to process those fluctuating pressure signals obtained. On these bases, the characteristics of pressure fluctuations acting on the tongue were discussed. It is found that aliasing errors decrease at higher sampling frequency of 17 640 Hz, but not at a lower sampling frequency of 1 764 Hz. Correspondingly, an output frequency range ten-times wider is obtained at 17 640 Hz. Compared with 8R, when the sampling time is shorter, the amplitudes may be overvalued, and the frequencies and amplitudes of low-frequency fluctuations can not be well predicted. The frequencies at the tongue are in good agreement with the values calculated by formula and the frequency compositions less than the blade passing frequency are accurately predicted.展开更多
This paper presents a systematic model test program to assess the uncertainty of the ship-bank interaction forces,using the planar motion mechanism(PMM)system in a circulating water channel(CWC).Therefore,the uncertai...This paper presents a systematic model test program to assess the uncertainty of the ship-bank interaction forces,using the planar motion mechanism(PMM)system in a circulating water channel(CWC).Therefore,the uncertainties due to ship-bank distance and water depth are considered,and they are calculated via the partial differentials of the regression formulae based on the test data.The general part of the uncertainty analysis(UA)is performed according to the ITTC recommended procedure 7.5-02-06.04,while the uncertainty of speed is identified as the bias limit due to the flow velocity maldistribution in the CWC.In each example test for the UA of ship-bank interaction forces,12 repeated measurements were conducted.Results from the UA show that the contribution of water depth error and flow velocity maldistribution to the total uncertainty is noticeable,and the paper explains how they increase with the change of the test conditions.The present study will be useful in understanding the uncertainty regarding the ship-bank interaction force measurement in a CWC.展开更多
Traditional open circulating cooling water systems use a lot of water and electricity to remove waste heat.In coastal areas,closed seawater circulating cooling water systems have been used as an alternative to improve...Traditional open circulating cooling water systems use a lot of water and electricity to remove waste heat.In coastal areas,closed seawater circulating cooling water systems have been used as an alternative to improve cooling efficiency.However,a comprehensive comparison of the design and advantages of the two types of cooling systems is lacking.Also,the best way to match and optimize the seawater system with the circulating water system in the closed seawater circulating cooling water system has not been fully explored.In this paper,a closed seawater cooling system under multiperiod is constructed,taking into account monthly changes in environmental factors.The mixed integer nonlinear programming model is solved by using GAMS software to evaluate and compare the economics and operability of the two cooling schemes.Meanwhile,the matching relationship of the internal subsystems of the closed seawater circulating cooling water system after coupling the air coolers is studied in depth,and the cooling load is allocated reasonably.The cases show that seawater cooling saves 9.22%of circulating water and reduces the total cost by 8.93%compared with cooling tower.The cost of the closed seawater cooling system can be reduced by 24.37%after coupling air coolers,and there is a direct corresponding matching relationship between circulating water and seawater.展开更多
In order to solve water resources problems in the North China Plain, this paper explored human-nature compound water circulation system from three aspects including urban flood control, surface drainage and saline wat...In order to solve water resources problems in the North China Plain, this paper explored human-nature compound water circulation system from three aspects including urban flood control, surface drainage and saline water in the central and eastern of the North China Plain. Results show that:(1) The technical methods have achieved zero increase in rainwater runoff in urban areas,(2) surface drainage depletion problems can be solved through abandoned water and river water separation method,(3) and technical method through promoting rainwater infiltration would be used to solve problem of saline water in the central and eastern parts. This research provides a new perspective to the ultimate solutions to water resources problems in the North China Plain, and a fresh research direction for the development of hydro-geological science.展开更多
Recently, the increasing concern about the environmental quality of human settlements makes people realize that the attractive environment given by natural ecology also deficiently needs the feedback and protection of...Recently, the increasing concern about the environmental quality of human settlements makes people realize that the attractive environment given by natural ecology also deficiently needs the feedback and protection of nature in some forms so that the natural ecology can be endlessly cycled on its own. Taking the project of German Enterprise Center in Qingdao Sino-German Ecopark as an example, this paper discussed construction of outdoor environment water circulation system using the landscape building method.展开更多
As is known to all, resource conservation and environmental protection have become the main theme of our society today. Industrial enterprises need to use a large amount of water resources. The issue of "water re...As is known to all, resource conservation and environmental protection have become the main theme of our society today. Industrial enterprises need to use a large amount of water resources. The issue of "water resource conservation and environmental protection" in industrial cooling circulating water treatment is beginning to be paid more and more attention. In this paper, the patent product "a multifunctional bio-pharmaceutical water treatment agent" with high efficiency, energy conservation and environmental protection is cited to explore its application and development prospect in industrial cooling circulating water treatment of power plants. In the future, with the improvement of biological water treatment agent and its supporting equipment, the biological water treatment agent will be promoted and popularized to better protect the water environment.展开更多
After water is impounded in a reservoir, rock mass in the hydro-fluctuation belt of the reservoir bank slope is subject to water saturation- dehydration circulation （WSDC）. To quantify the rate of change of rock mec...After water is impounded in a reservoir, rock mass in the hydro-fluctuation belt of the reservoir bank slope is subject to water saturation- dehydration circulation （WSDC）. To quantify the rate of change of rock mechanical properties, samples from the Longtan dam area were measured with uniaxial compression tests after different numbers （1, 5, 10, 15, and 20） of simulated WSDC cycles. Based on the curves derived from these tests, a modified Hock- Brown failure criterion was proposed, in which a new parameter was introduced to model the cumulative damage to rocks after WSDC. A case of an engineering application was analyzed, and the results showed that the modified Hock-Brown failure criterion is useful. Under similar WSDC-influenced engineering and geological conditions, rock mass strength parameters required for analysis and evaluation of rock slope stability can be estimated according to this modified Hoek-Brown failure criterion.展开更多
With urbanization accelerating, people’s living standard is growing and their demands on lifestyle are improving accordingly. The research proposed housing gardening system based on low-carbon greenhouse technology f...With urbanization accelerating, people’s living standard is growing and their demands on lifestyle are improving accordingly. The research proposed housing gardening system based on low-carbon greenhouse technology from perspectives of air quality, food safety and environment-friendliness. Besides, the research detailed designs of planting system, water circulation system and lighting system by interpretation on low-carbon greenhouse technology, microclimate and housing gardening system.展开更多
The characteristics of the T/S structures,water mass exchange and deep circulation in the Andaman Sea are investigated based on the simulation from a high-resolution general circulation model(MITgcm).The results show ...The characteristics of the T/S structures,water mass exchange and deep circulation in the Andaman Sea are investigated based on the simulation from a high-resolution general circulation model(MITgcm).The results show that,below 1000 m,the water mass is saltier,warmer and more homogeneous in the Andaman Sea than that in the Bay of Bengal,attributing to the strong vertical mixing at the depth of^1800 m.The water mass exchange between the Andaman Sea and the Bay of Bengal goes through three major channels,which manifests itself as follows:the northern channel(Preparis Channel)is the main passage of water mass transport from the Bay of Bengal to the Andaman Sea,whereas the Middle Channel(the south of Andaman Islands and the north of Nicobar Islands)has an opposite transport;the southern channel(Great Channel)features with a four-layer water exchange which results in the least net transport among the three channels;all the transports through the three channels have an intra-annual variation with a period of half a year.At 1000-m depth,the entire Andaman Sea is occupied by a cyclonic circulation in January and July while by an anticyclonic one in April and October.The semiannual cycle found in both the deep circulation and water mass exchange is likely associated with the downwelling eastward-propagating Kelvin waves induced by the semiannual westerly component in the equatorial Indian Ocean during intermonsoon seasons.展开更多
Based on the characteristic of ‘one river one oasis’ in the arid areas, the Yerqiang River Basin, which is the largest irrigated area of Xinjiang, is taken as an example in this paper, and the regional water circula...Based on the characteristic of ‘one river one oasis’ in the arid areas, the Yerqiang River Basin, which is the largest irrigated area of Xinjiang, is taken as an example in this paper, and the regional water circulation pattern is investigated through the analysis of 60 groups of isotope data in the basin. From the phreatic evaporation data analysis of different soils, we study the law of phreatic evaporation, complete the research of the main consumption path of the groundwater, and improve the assessment precision of water resources. The transformation mount of regional water resources are predicted by calculation, which provides a scientific basis for water resources assessment and allocation in arid regions, and offers a new method for the study of regional water circulation patterns.展开更多
On the basis of the salinity distribution of isopycnal（σ_0=27.2 kg/m^3） surface and in salinity minimum, the Antarctic Intermediate Water（AAIW） around South Australia can be classified into five types correspondi...On the basis of the salinity distribution of isopycnal（σ_0=27.2 kg/m^3） surface and in salinity minimum, the Antarctic Intermediate Water（AAIW） around South Australia can be classified into five types corresponding to five regions by using in situ CTD observations. Type 1 is the Tasman AAIW, which has consistent hydrographic properties in the South Coral Sea and the North Tasman Sea. Type 2 is the Southern Ocean（SO） AAIW, parallel to and extending from the Subantarctic Front with the freshest and coldest AAIW in the study area. Type 3 is a transition between Type 1 and Type 2. The AAIW transforms from fresh to saline with the latitude declining（equatorward）. Type 4, the South Australia AAIW, has relatively uniform AAIW properties due to the semienclosed South Australia Basin. Type 5, the Southeast Indian AAIW, progressively becomes more saline through mixing with the subtropical Indian intermediate water from south to north. In addition to the above hydrographic analysis of AAIW, the newest trajectories of Argo（Array for real-time Geostrophic Oceanography） floats were used to constructed the intermediate（1 000 m water depth） current field, which show the major interocean circulation of AAIW in the study area. Finally, a refined schematic of intermediate circulation shows that several currents get together to complete the connection between the Pacific Ocean and the Indian Ocean. They include the South Equatorial Current and the East Australia Current in the Southwest Pacific Ocean, the Tasman Leakage and the Flinders Current in the South Australia Basin, and the extension of Flinders Current in the southeast Indian Ocean.展开更多
Systematical analysis on factors affecting the cold end system in power plants was conducted.The optimization model was obtained,which regarded the minimum net coal consumption rate as the objectivefunction,used sever...Systematical analysis on factors affecting the cold end system in power plants was conducted.The optimization model was obtained,which regarded the minimum net coal consumption rate as the objectivefunction,used several objective conditions as the variables,such as flow rate and temperature of the circu-lating water,supercooling degree of the condenser,fouling and air leakage in the condenser.Genetic algo-rithm was employed to optimize the multiple factors affecting the cold end system,and the optimizationconditions for the minimum net coal consumption rate and the corresponding parameters were obtained.Comparison indicated that this genetic algorithm not only can optimize the cold end system quickly and ac-curately,but also can compensate the economic efficiency drop that caused by defects of some parametersthrough automatic adjustment of the parameters.展开更多
Based on the observed data of soil moisture from locating experiments from 1986 to 1990, the pattern of field water circulation in dryland of northern China, where the mean annual precipitation is 300 600 mm, is stud...Based on the observed data of soil moisture from locating experiments from 1986 to 1990, the pattern of field water circulation in dryland of northern China, where the mean annual precipitation is 300 600 mm, is studied in this paper using the method of water balance. The results show that water satisfying ratio of spring seeding crops is 83.7 90.8 percent and that of winter wheat is about 70 percent in these areas; about 80 90 percent of water consumption of spring seeding crops and about 60 70 percent of water consumption of winter wheat comes from precipitation during the growing period, the rest comes from the soil water storage before the seeding period. But the available soil water is not used thoroughly, about 30 70 percent of available soil water remains unused when the crops are harvested. At the fallow period, the amount of soil water lost by evaporation is very important, which takes up 57 68 percent of precipitation in winter wheat field and 73 244 percent in field of spring seeding crops. Thus restraining soil evaporation, raising the storage ratio of natural precipitation and the soil water utilization efficiency of crops, strengthening the circulation ability of soil water by adopting efficient measures of agricultural techniques, are the main ways for exploiting and developing the potential productivity of natural precipitation in these areas.展开更多
文摘Cold rolling circulating water station mainly supplies circulating cooling water for each unit in the cold rolling plant. The actual operation condition of circulating water pump deviates from the design, and the water pump runs away from the high efficiency zone. The existing problems in operation are analyzed, and corresponding measures are taken, which greatly reduces the energy consumption of the pumping station and achieves good results.
文摘Since the treatment of circulating water will directly affect the discharge of chemical enterprises, the treatment of circulating water is an important link in the development of chemical enterprises, and the cooling tower is the decisive factor to determine the temperature of circulating water. Therefore, it is necessary to analyze the problems existing in the cooling tower, and put forward corresponding countermeasures for the problems existing in the operation of circulating water cooling tower, so as to explore a reasonable solution.
基金Financial support from the National Natural Science Foundation of China (22022816 and 22078358)
文摘Fouling caused by excess metal ions in hard water can negatively impact the performance of the circulating cooling water system(CCWS)by depositing ions on the heat exchanger's surface.Currently,the operation optimization of CCWS often prioritizes short-term flow velocity optimization for minimizing power consumption,without considering fouling.However,low flow velocity promotes fouling.Therefore,it's crucial to balance fouling and energy/water conservation for optimal CCWS long-term operation.This study proposes a mixed-integer nonlinear programming(MINLP)model to achieve this goal.The model considers fouling in the pipeline,dynamic concentration cycle,and variable frequency drive to optimize the synergy between heat transfer,pressure drop,and fouling.By optimizing the concentration cycle of the CCWS,water conservation and fouling control can be achieved.The model can obtain the optimal operating parameters for different operation intervals,including the number of pumps,frequency,and valve local resistance coefficient.Sensitivity experiments on cycle and environmental temperature reveal that as the cycle increases,the marginal benefits of energy/water conservation decrease.In periods with minimal impact on fouling rate,energy/water conservation can be achieved by increasing the cycle while maintaining a low fouling rate.Overall,the proposed model has significant energy/water saving effects and can comprehensively optimize the CCWS through its incorporation of fouling and cycle optimization.
基金Financial support from the National Natural Science Foundation of China (22022816, 22078358)。
文摘Recent research on deterministic methods for circulating cooling water systems optimization has been well developed. However, the actual operating conditions of the system are mostly variable, so the system obtained under deterministic conditions may not be stable and economical. This paper studies the optimization of circulating cooling water systems under uncertain circumstance. To improve the reliability of the system and reduce the water and energy consumption, the influence of different uncertain parameters is taken into consideration. The chance constrained programming method is used to build a model under uncertain conditions, where the confidence level indicates the degree of constraint violation. Probability distribution functions are used to describe the form of uncertain parameters. The objective is to minimize the total cost and obtain the optimal cooling network configuration simultaneously.An algorithm based on Monte Carlo method is proposed, and GAMS software is used to solve the mixed integer nonlinear programming model. A case is optimized to verify the validity of the model. Compared with the deterministic optimization method, the results show that when considering the different types of uncertain parameters, a system with better economy and reliability can be obtained(total cost can be reduced at least 2%).
基金supported by the Foundation for Top Talents Program of China University of Petroleum
文摘Mesoporous SiO_2 microspheres were synthesized using the sol-gel method and were characterized by TEM, FT-IR and BET techniques. The diameter of the microspheres is about 100—150 nm, and the average mesopore diameter is 2.55 nm, while the specific surface area is 1 088.9 m2/g. Mesoporous SiO_2 microspheres adsorb glutaraldehyde and immobilize laccase by means of the aldehyde group in glutaral which can react with the amidogen of laccase. The immobilization conditions were optimized at a glutaraldehyde concentration of 0.75%, a crosslinking time of 8 h, a laccase concentration of 0.04 L/L and an immobilization time of 10 h. When diesel leakage concentration was 80 mg/L, the highest corrosion inhibition efficiency of immobilized laccase reached 49.23%, which was slightly lower than the corrosion inhibition efficiency of free laccase(59%). The diesel degradation ratio could reach up to 45%. It has been proved that the immobilized laccase could degrade diesel to inhibit corrosion.
基金the support from Natural Science Foundation of Heilongjiang Province(No.YQ2022A004)National Natural Science Foundation of China(No.12372268,No.12332014).
文摘As intelligent sensors for marine applications rapidly advance,there is a growing emphasis on developing efficient,low-cost,and sustainable power sources to enhance their performance.With the continuous development of triboelectric nanogenerators(TENGs),known for their simple structure and versatile operational modes,these devices exhibit promising technological potential and have garnered extensive attention from a broad spectrum of researchers.The single-electrode mode of TENGs presents an effective means to harness eco-friendly energy sourced from flowing water.In this study,the factors affecting the output performance were investigated using different structures of single-electrode solid-liquid TENGs placed in a circulating water tank.In addition,the solid‒liquid contact process was numerically simulated using the COMSOL Multiphysics software,and significant potential energy changes were obtained for the solid‒liquid contact and liquid flow processes.Finally,the energy generated is collected and converted to power several light-emitting diodes,demonstrating that solid‒liquid TENGs can generate effective electrical power in a flowing water environment.Through several experimental investigations,we finally determined that the flow rate of the liquid,the thickness of the friction electrode material,and the contact area have the most significant effect on the output efficiency of TENGs in the form of flowing water,which provides a guide for improving their performance in the future.
基金Project supported by the Priority Academic Development Program of Jiangsu Higher Education Institutions, ChinaProject(CXZZ12_0680) supported by Postgraduate Innovation Foundation of Jiangsu Province, ChinaProject(12JDG082) supported by the Advanced Talent Foundation of Jiangsu University, China
文摘In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbulence models with hydraulic performance experiment, SST k-co model was confirmed to study the rational determination of sampling frequency and time better. The Fast Fourier Transform （FFT） technology was then adopted to process those fluctuating pressure signals obtained. On these bases, the characteristics of pressure fluctuations acting on the tongue were discussed. It is found that aliasing errors decrease at higher sampling frequency of 17 640 Hz, but not at a lower sampling frequency of 1 764 Hz. Correspondingly, an output frequency range ten-times wider is obtained at 17 640 Hz. Compared with 8R, when the sampling time is shorter, the amplitudes may be overvalued, and the frequencies and amplitudes of low-frequency fluctuations can not be well predicted. The frequencies at the tongue are in good agreement with the values calculated by formula and the frequency compositions less than the blade passing frequency are accurately predicted.
基金This study is financially supported by the China Ministry of Education Key Research Project“KSHIP-II Project”(Grant No.GKZY010004).
文摘This paper presents a systematic model test program to assess the uncertainty of the ship-bank interaction forces,using the planar motion mechanism(PMM)system in a circulating water channel(CWC).Therefore,the uncertainties due to ship-bank distance and water depth are considered,and they are calculated via the partial differentials of the regression formulae based on the test data.The general part of the uncertainty analysis(UA)is performed according to the ITTC recommended procedure 7.5-02-06.04,while the uncertainty of speed is identified as the bias limit due to the flow velocity maldistribution in the CWC.In each example test for the UA of ship-bank interaction forces,12 repeated measurements were conducted.Results from the UA show that the contribution of water depth error and flow velocity maldistribution to the total uncertainty is noticeable,and the paper explains how they increase with the change of the test conditions.The present study will be useful in understanding the uncertainty regarding the ship-bank interaction force measurement in a CWC.
基金support from the National Natural Science Foundation of China under Grant(Grant Nos.22393954 and 22078358)is gratefully acknowledged.
文摘Traditional open circulating cooling water systems use a lot of water and electricity to remove waste heat.In coastal areas,closed seawater circulating cooling water systems have been used as an alternative to improve cooling efficiency.However,a comprehensive comparison of the design and advantages of the two types of cooling systems is lacking.Also,the best way to match and optimize the seawater system with the circulating water system in the closed seawater circulating cooling water system has not been fully explored.In this paper,a closed seawater cooling system under multiperiod is constructed,taking into account monthly changes in environmental factors.The mixed integer nonlinear programming model is solved by using GAMS software to evaluate and compare the economics and operability of the two cooling schemes.Meanwhile,the matching relationship of the internal subsystems of the closed seawater circulating cooling water system after coupling the air coolers is studied in depth,and the cooling load is allocated reasonably.The cases show that seawater cooling saves 9.22%of circulating water and reduces the total cost by 8.93%compared with cooling tower.The cost of the closed seawater cooling system can be reduced by 24.37%after coupling air coolers,and there is a direct corresponding matching relationship between circulating water and seawater.
基金funded by National Key Basic Research Program of China(2010CB428800),Geological Survey(20023064)(12120113102400)
文摘In order to solve water resources problems in the North China Plain, this paper explored human-nature compound water circulation system from three aspects including urban flood control, surface drainage and saline water in the central and eastern of the North China Plain. Results show that:(1) The technical methods have achieved zero increase in rainwater runoff in urban areas,(2) surface drainage depletion problems can be solved through abandoned water and river water separation method,(3) and technical method through promoting rainwater infiltration would be used to solve problem of saline water in the central and eastern parts. This research provides a new perspective to the ultimate solutions to water resources problems in the North China Plain, and a fresh research direction for the development of hydro-geological science.
基金Sponsored by the National Science and Technology Project in the Twelfth Five-Year Plan Period(2013BAJ02B04)
文摘Recently, the increasing concern about the environmental quality of human settlements makes people realize that the attractive environment given by natural ecology also deficiently needs the feedback and protection of nature in some forms so that the natural ecology can be endlessly cycled on its own. Taking the project of German Enterprise Center in Qingdao Sino-German Ecopark as an example, this paper discussed construction of outdoor environment water circulation system using the landscape building method.
文摘As is known to all, resource conservation and environmental protection have become the main theme of our society today. Industrial enterprises need to use a large amount of water resources. The issue of "water resource conservation and environmental protection" in industrial cooling circulating water treatment is beginning to be paid more and more attention. In this paper, the patent product "a multifunctional bio-pharmaceutical water treatment agent" with high efficiency, energy conservation and environmental protection is cited to explore its application and development prospect in industrial cooling circulating water treatment of power plants. In the future, with the improvement of biological water treatment agent and its supporting equipment, the biological water treatment agent will be promoted and popularized to better protect the water environment.
基金supported by the National Natural Science Foundation of China under No. 41630639the National Basic Research Program of China (2014CB744703)+1 种基金Natural Science Basic Research Plan in Shaanxi Province of China (No. 2016JQ4014)China Postdoctoral Science Foundation (2016M602743)
文摘After water is impounded in a reservoir, rock mass in the hydro-fluctuation belt of the reservoir bank slope is subject to water saturation- dehydration circulation （WSDC）. To quantify the rate of change of rock mechanical properties, samples from the Longtan dam area were measured with uniaxial compression tests after different numbers （1, 5, 10, 15, and 20） of simulated WSDC cycles. Based on the curves derived from these tests, a modified Hock- Brown failure criterion was proposed, in which a new parameter was introduced to model the cumulative damage to rocks after WSDC. A case of an engineering application was analyzed, and the results showed that the modified Hock-Brown failure criterion is useful. Under similar WSDC-influenced engineering and geological conditions, rock mass strength parameters required for analysis and evaluation of rock slope stability can be estimated according to this modified Hoek-Brown failure criterion.
文摘With urbanization accelerating, people’s living standard is growing and their demands on lifestyle are improving accordingly. The research proposed housing gardening system based on low-carbon greenhouse technology from perspectives of air quality, food safety and environment-friendliness. Besides, the research detailed designs of planting system, water circulation system and lighting system by interpretation on low-carbon greenhouse technology, microclimate and housing gardening system.
基金The National Natural Science Foundation of China under contract Nos 41931182,41521005 and 41676016Guangdong Key Project under contract No.2019BT2H594+2 种基金the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract Nos GML2019ZD0303 and GML2019ZD0304the Chinese Academy of Sciences under contract Nos ZDRW-XH-2019-2 and ISEE2018PY05the Independent Research Project Program of State Key Laboratory of Tropical Oceanography under contract Nos LTOZZ1902 and LTOZZ1802。
文摘The characteristics of the T/S structures,water mass exchange and deep circulation in the Andaman Sea are investigated based on the simulation from a high-resolution general circulation model(MITgcm).The results show that,below 1000 m,the water mass is saltier,warmer and more homogeneous in the Andaman Sea than that in the Bay of Bengal,attributing to the strong vertical mixing at the depth of^1800 m.The water mass exchange between the Andaman Sea and the Bay of Bengal goes through three major channels,which manifests itself as follows:the northern channel(Preparis Channel)is the main passage of water mass transport from the Bay of Bengal to the Andaman Sea,whereas the Middle Channel(the south of Andaman Islands and the north of Nicobar Islands)has an opposite transport;the southern channel(Great Channel)features with a four-layer water exchange which results in the least net transport among the three channels;all the transports through the three channels have an intra-annual variation with a period of half a year.At 1000-m depth,the entire Andaman Sea is occupied by a cyclonic circulation in January and July while by an anticyclonic one in April and October.The semiannual cycle found in both the deep circulation and water mass exchange is likely associated with the downwelling eastward-propagating Kelvin waves induced by the semiannual westerly component in the equatorial Indian Ocean during intermonsoon seasons.
文摘Based on the characteristic of ‘one river one oasis’ in the arid areas, the Yerqiang River Basin, which is the largest irrigated area of Xinjiang, is taken as an example in this paper, and the regional water circulation pattern is investigated through the analysis of 60 groups of isotope data in the basin. From the phreatic evaporation data analysis of different soils, we study the law of phreatic evaporation, complete the research of the main consumption path of the groundwater, and improve the assessment precision of water resources. The transformation mount of regional water resources are predicted by calculation, which provides a scientific basis for water resources assessment and allocation in arid regions, and offers a new method for the study of regional water circulation patterns.
基金The Chinese Polar Environment Comprehensive Investigation and Assessment Programs under contract Nos CHINARE-04-04 and CHINARE-04-01
文摘On the basis of the salinity distribution of isopycnal（σ_0=27.2 kg/m^3） surface and in salinity minimum, the Antarctic Intermediate Water（AAIW） around South Australia can be classified into five types corresponding to five regions by using in situ CTD observations. Type 1 is the Tasman AAIW, which has consistent hydrographic properties in the South Coral Sea and the North Tasman Sea. Type 2 is the Southern Ocean（SO） AAIW, parallel to and extending from the Subantarctic Front with the freshest and coldest AAIW in the study area. Type 3 is a transition between Type 1 and Type 2. The AAIW transforms from fresh to saline with the latitude declining（equatorward）. Type 4, the South Australia AAIW, has relatively uniform AAIW properties due to the semienclosed South Australia Basin. Type 5, the Southeast Indian AAIW, progressively becomes more saline through mixing with the subtropical Indian intermediate water from south to north. In addition to the above hydrographic analysis of AAIW, the newest trajectories of Argo（Array for real-time Geostrophic Oceanography） floats were used to constructed the intermediate（1 000 m water depth） current field, which show the major interocean circulation of AAIW in the study area. Finally, a refined schematic of intermediate circulation shows that several currents get together to complete the connection between the Pacific Ocean and the Indian Ocean. They include the South Equatorial Current and the East Australia Current in the Southwest Pacific Ocean, the Tasman Leakage and the Flinders Current in the South Australia Basin, and the extension of Flinders Current in the southeast Indian Ocean.
基金National Key Technology Research and Development Program of Ministry of Science and Technology of China(2011BAA04B03)
文摘Systematical analysis on factors affecting the cold end system in power plants was conducted.The optimization model was obtained,which regarded the minimum net coal consumption rate as the objectivefunction,used several objective conditions as the variables,such as flow rate and temperature of the circu-lating water,supercooling degree of the condenser,fouling and air leakage in the condenser.Genetic algo-rithm was employed to optimize the multiple factors affecting the cold end system,and the optimizationconditions for the minimum net coal consumption rate and the corresponding parameters were obtained.Comparison indicated that this genetic algorithm not only can optimize the cold end system quickly and ac-curately,but also can compensate the economic efficiency drop that caused by defects of some parametersthrough automatic adjustment of the parameters.
文摘Based on the observed data of soil moisture from locating experiments from 1986 to 1990, the pattern of field water circulation in dryland of northern China, where the mean annual precipitation is 300 600 mm, is studied in this paper using the method of water balance. The results show that water satisfying ratio of spring seeding crops is 83.7 90.8 percent and that of winter wheat is about 70 percent in these areas; about 80 90 percent of water consumption of spring seeding crops and about 60 70 percent of water consumption of winter wheat comes from precipitation during the growing period, the rest comes from the soil water storage before the seeding period. But the available soil water is not used thoroughly, about 30 70 percent of available soil water remains unused when the crops are harvested. At the fallow period, the amount of soil water lost by evaporation is very important, which takes up 57 68 percent of precipitation in winter wheat field and 73 244 percent in field of spring seeding crops. Thus restraining soil evaporation, raising the storage ratio of natural precipitation and the soil water utilization efficiency of crops, strengthening the circulation ability of soil water by adopting efficient measures of agricultural techniques, are the main ways for exploiting and developing the potential productivity of natural precipitation in these areas.
