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Numerical Analysis of Phase Change and Container Materials for Thermal Energy Storage in the Storage Tank of Solar Water Heating System
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作者 SINGH Shailendra ANAND Abhishek +1 位作者 SHUKLA Amritanshu SHARMA Atul 《Journal of Thermal Science》 SCIE EI CAS CSCD 2024年第2期408-421,共14页
This study evaluates the effectiveness of phase change materials(PCMs) inside a storage tank of warm water for solar water heating(SWH) system through the theoretical simulation based on the experimental model of S.Ca... This study evaluates the effectiveness of phase change materials(PCMs) inside a storage tank of warm water for solar water heating(SWH) system through the theoretical simulation based on the experimental model of S.Canbazoglu et al.The model is explained by five fundamental equations for the calculation of various parameters like the effectiveness of PCMs,the mass of hot water,total heat content,and duration of charging.This study simulated eleven PCMs to analyze their effectiveness like Sodium hydrogen phosphate dodecahydrate(SHPD),OM 37,N-Eicosane(NE),Lauric acid(LA),Paraffin wax(PW),OM 48,Paraffin wax C_(20-33)(PW-C20-33),Sodium acetate trihydrate(SAT),Palmitic acid(PA),Myristic acid(MA),and Stearic acid(SA).Among all PCMs,the SHPD has found the highest value of effectiveness factor of 3.27.So,it is the most recommended PCM for the storage tank of the SWH system.The study also includes the melt fraction analysis of all enumerated PCMs corresponding to container materials of stainless steel,glass,aluminum mixed,tin,aluminum,and copper.This melt fraction analysis is performed by making a coding program in the FORTRAN programming language.Through the analysis,copper container material is found to have high melting rate for all PCMs so it is superior to other container materials. 展开更多
关键词 theoretical model solar water heating system phase change material effectiveness factor melt fraction
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Potential application of a novel building-integrated solar facade water heating system in a subtropical climate:A case study for school canteen
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作者 Wenjie Liu Xinwen Liu +3 位作者 Chongchao Pan Chunying Li Woonming Lau Yuanli Lyu 《Building Simulation》 SCIE EI CSCD 2023年第10期1987-2004,共18页
The design and potential application analysis of the novel solar-absorbing integrated facade module and its corresponding building-integrated solar facade water heating system are presented in this study.Compared with... The design and potential application analysis of the novel solar-absorbing integrated facade module and its corresponding building-integrated solar facade water heating system are presented in this study.Compared with the conventional building envelope,the main novities of the proposed facade module lie in its contributions towards the supplied water preheating to loads and the internal heat gain reduction.Besides,the proposed building-integrated solar facade water heating system broadens the combination modes of the solar thermal system and the building envelope.A dynamic model is introduced first for system design and performance prediction.To evaluate the energy-saving potential and feasibility of the implementation of the proposed facade module,this paper carried out a suitable case study by replacing the conventional facade module in the ongoing retrofitting project of a kitchen,part of the canteen of a graduate school.The detailed thermal performances of three system design options are compared in the typical winter and summer weeks and throughout the year,and then,with the preferred system design,the economic,energy,and environmental effects of the proposed system are evaluated.It was found that the system with a high flow rate of the circulating water is suggested.The annual electricity saved reaches 4175.3 kWh with yearly average thermal efficiency at 46.9%,and its corresponding cost payback time,energy payback time,and greenhouse gas payback time are 3.8,1.7,1.7 years,respectively.This study confirms the feasibility and long-term benefits of the proposed building-integrated solar facade water heating system in buildings. 展开更多
关键词 solar thermal utilization building-integrated solar water heating system novel prefabricated facade module life cycle assessment building retrofitting
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Energy Efficient Air Conditioning System Using Geothermal Cooling-Solar Heating in Gujarat, India 被引量:1
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作者 Sneha Shahare T. Harinarayana 《Journal of Power and Energy Engineering》 2016年第1期57-71,共15页
It is well known that one unit of electrical energy saved is equal to more than two units produced. One way of economizing the power is utilization of energy efficient systems at all locations. In the present study, t... It is well known that one unit of electrical energy saved is equal to more than two units produced. One way of economizing the power is utilization of energy efficient systems at all locations. In the present study, the air conditioning system is analysed and an innovative way is suggested. We use natural low temperature of shallow sub surface (1 - 3 m) of the earth—geothermal cooling system. It is known that majority of the households and the apartment complexes in India have two tanks for water storage. One is the underground water sump and the other is the overhead water tank. In our study, we use these two water storage systems for space cooling during summer and also for heating during winter. The main aim of our paper is air-conditioning of the space in an economic way to save electricity. It is based on a simple idea of transferring the low temperature from underground water sump to the room in the house using water as a mode of transport. Since India is a tropical country located at low latitude, most of the year, the air temperature is high and demands space cooling. However, for a couple of months during severe winter months (Dec.-Jan.) at Ahmedabad, heating of the space is required. For heating the space, we suggest to use the well-known solar water heater. Effective use of heat exchanger is shown through computation, modelling schemes and lab experiment. We recommend geothermal cooling for 10 months in a year and solar hot water system during 2 months of winter. It is observed that the ambient air temperature of 35°C - 40°C in the room can be brought down to 26°C without much consumption of electricity. In a similar manner, the room temperature at night (13°C) during winter in Ahmedabad can be increased to 27°C through circulation of water from solar water heater in the heat exchanger. 展开更多
关键词 Energy Efficiency Geothermal Cooling Air Conditioning CFD Thermal Comfort Earth water Heat Exchanger
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Heating of Nanosized Liquid Water in High-Intensity Terahertz Pulses
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作者 黄自谦 杨荣瑶 +1 位作者 蒋维洲 章其林 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第1期36-39,共4页
Non-equilibrium molecular dynamics simulations of liquid water in picosecond high-power terahertz pulses are performed by using a non-polarizable potential model. Numerical results show that the energy absorption of w... Non-equilibrium molecular dynamics simulations of liquid water in picosecond high-power terahertz pulses are performed by using a non-polarizable potential model. Numerical results show that the energy absorption of water molecules exhibits a pronounced resonance with THz pulses in the frequency range of 14-17 THz. With the THz pulse at resonant frequencies, the maximum temperature is about 562 K by heating the water at room temperature. Further investigation indicates that the results are independent of the size of the nanoscale water box. The efficiency of energy transfer by resonant absorption is more than seven times of microwave heating. These studies show promising applications of ultrashort THz pulses. 展开更多
关键词 of on heating of Nanosized Liquid water in High-Intensity Terahertz Pulses THz in is that
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Overview of China's National Standards for Solar Water Heating
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作者 JIA Tieying 《China Standardization》 2007年第5期6-11,共6页
  Introduction   Energy supply is one of the major challenges facing China. The rate at which demand is outstripping supply led the Standing Committee of the National People's Congress to pass the Renewable E...   Introduction   Energy supply is one of the major challenges facing China. The rate at which demand is outstripping supply led the Standing Committee of the National People's Congress to pass the Renewable Energy Law of the PRC at its fourteenth session in February, 2005.…… 展开更多
关键词 Overview of China’s National Standards for Solar water heating
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Experimental Investigation on Solution Regeneration Performance and Coefficients in Full-Open System for Heat and Water Recovery of Flue Gas
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作者 WEI Hongyang HUANG Shifang +3 位作者 MA Yuxin CHEN Bo SUN Li ZHANG Xiaosong 《Journal of Thermal Science》 SCIE EI CAS CSCD 2024年第3期1094-1108,共15页
The recovery of heat and water from low-grade flue gas is of considerable importance for energy conservation and environmental preservation.While the full-open absorption heat pump shows promise as a means of achievin... The recovery of heat and water from low-grade flue gas is of considerable importance for energy conservation and environmental preservation.While the full-open absorption heat pump shows promise as a means of achieving heat and water recovery,the lack of research on heat and mass transfer performance of open-type solution evaporation regeneration represents a significant impediment to its design and operation.This paper experimentally investigates the regeneration performance of an open-type spaying tower equipped with ceramic structured packings.Two different regeneration modes are proposed,namely ambient air receiver mode and flue gas receiver mode,to utilize air or low-grade flue gas as a driving source.The impact of different input parameters on the regeneration characteristics,including heat transfer capacity,water removal rate,thermal efficiency,and humidity effectiveness,are demonstrated.The findings indicate that the enhancement of regeneration can be achieved through the increase of solution flow rate,solution temperature,and flue gas flow rate in both regeneration modes.However,high solution concentration and flue gas humidity ratio can weaken water removal rates and reduce thermal efficiency.For the regeneration of CaCl_(2)-H_(2)O with a concentration of55%,flue gas around 200℃with a humidity ratio below 44 g/kg can successfully drive the solution regeneration process.When the solution concentration or flue gas humidity ratio continues to rise,additional energy is necessary for regeneration.Furthermore,the coupled heat and mass transfer coefficients are fitted,which can contribute to the design and optimization of the open-type regenerator. 展开更多
关键词 heat and water recovery solution regeneration flue gas regeneration performance coefficient
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Performance and Optimization of Air Source Heat Pump Water Heater with Cyclic Heating
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作者 李凡 陆高锋 +3 位作者 丁云霄 郑春元 李斌 翟晓强 《Journal of Shanghai Jiaotong university(Science)》 EI 2024年第2期179-187,共9页
A new type of microchannel condenser applied in the air source heat pump water heater(ASHPWH)with cyclic heating was proposed in this study.The operating performance of the ASHPWH was frst tested.Then,the structure of... A new type of microchannel condenser applied in the air source heat pump water heater(ASHPWH)with cyclic heating was proposed in this study.The operating performance of the ASHPWH was frst tested.Then,the structure of the microchannel condenser was optimized with the implement of vortex generators.Finally,a numerical model of the ASHPWH was established and the optimized microchannel condenser was studied.The experimental results showed that the average coefficient of performance(COP)of the 1HP(735 W)ASHPWH reached 3.48.In addition,the optimized microchannel condenser could be matched with a 3 HP(2430W)ASHPWH with an average heating capacity of 10.30 kW,and achieving an average COP of 4.24,14.6%higher than the limit value in the national standard. 展开更多
关键词 air source heat pump water heater(ASHPWH) cyclic heating MICROCHANNEL CONDENSER
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Effects of biodegradable mulch on soil water and heat conditions,yield and quality of processing tomatoes by drip irrigation 被引量:2
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作者 JIA Hao WANG Zhenhua +4 位作者 ZHANG Jinzhu LI Wenhao REN Zuoli JIA Zhecheng WANG Qin 《Journal of Arid Land》 SCIE CSCD 2020年第5期819-836,共18页
To combat the problem of residual film pollution and ensure the sustainable development of agriculture in oasis areas,a field experiment was carried out in 2019 at the Wuyi Farm Corps Irrigation Center Test Station in... To combat the problem of residual film pollution and ensure the sustainable development of agriculture in oasis areas,a field experiment was carried out in 2019 at the Wuyi Farm Corps Irrigation Center Test Station in Urumqi,Northwest China.Four types of biodegradable mulches,traditional plastic mulchs and a control group(bare land;referred to as CK)were compared,including a total of six different treatments.Effects of mulching on soil water and heat conditions as well as the yield and quality of processing tomatoes under drip irrigation were examined.In addition,a comparative analysis of economic benefits of biodegradable mulches was performed.Principal component analysis and gray correlation analysis were used to evaluate suitable mulching varieties for planting processing tomatoes under drip irrigation.Our results show that,compared with CK,biodegradable mulches and traditional plastic mulch have a similar effect on retaining soil moisture at the seedling stage but significantly increase soil moisture by 0.5%-1.5%and 1.5%-3.0%in the middle and late growth periods(P<0.050),respectively.The difference in the thermal insulation effect between biodegradable mulch and plastic mulch gradually reduces as the crop grows.Compared with plastic mulch,the average soil temperature at 5-20 cm depth under biodegradable mulches is significantly lowered by 2.04°C-3.52°C and 0.52°C-0.88°C(P<0.050)at the seedling stage and the full growth period,respectively,and the water use efficiency,average fruit yield,and production-investment ratio under biodegradable mulches were reduced by 0.89%-6.63%,3.39%-8.69%,and 0.51%-6.33%(P<0.050),respectively.The comprehensive evaluation analysis suggests that the black oxidized biological double-degradation ecological mulch made from eco-benign plastic is the optimal film type under the study condition.Therefore,from the perspective of sustainable development,biodegradable mulch is a competitive alternative to plastic mulch for large-scale tomato production under drip irrigation in the oasis. 展开更多
关键词 biodegradable plastic mulch processing tomato water use efficiency soil water and heat comprehensive evaluation regional agricultural sustainability XINJIANG
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Different discretization method used in coupled water and heat transport mode for soil under freezing conditions 被引量:2
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作者 WeiNan Mao JianKun Liu 《Research in Cold and Arid Regions》 CSCD 2013年第4期413-417,共5页
A coupled water and heat transport mode is established based on the Richards equation to study water flow and heat transport in soil during freezing process. Both the finite difference and finite element method are us... A coupled water and heat transport mode is established based on the Richards equation to study water flow and heat transport in soil during freezing process. Both the finite difference and finite element method are used in the discretization, respectively. Two different computer programs are written and used to simulate an indoor unidirectional frozen test. The freezing depth, freezing rate and temperature variation are compared among lab tests, finite difference calculation simulation and finite element calculation simulation. Result shows that: the finite difference method has a better performance in freezing depth simulation while the finite element method has a better performance in numerical stability in one-dimensional freezing simulation. 展开更多
关键词 freezing soil coupled water and heat finite difference finite element freezing test simulation
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Modelling plant canopy effects on water-heat exchange in the freezingthawing processes of active layer on the Qinghai-Tibet Plateau 被引量:1
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作者 GUO Lin-mao CHANG Juan +1 位作者 XU Hong-liang SUN Wen-jun 《Journal of Mountain Science》 SCIE CSCD 2021年第6期1564-1579,共16页
The effect of vegetation on the water-heat exchange in the freezing-thawing processes of active layer is one of the key issues in the study of land surface processes and in predicting the response of alpine ecosystems... The effect of vegetation on the water-heat exchange in the freezing-thawing processes of active layer is one of the key issues in the study of land surface processes and in predicting the response of alpine ecosystems to climate change in permafrost regions. In this study, we used the simultaneous heat and water model to investigate the effects of plant canopy on surface and subsurface hydrothermal dynamics in the Fenghuoshan area of the QinghaiTibet Plateau by changing the leaf area index(LAI) and keeping other variables constant. Results showed that the sensible heat, latent heat and net radiation are increased with an increase in the LAI. However, the ground heat flux decreased with an increasing LAI. The annual total evapotranspiration and vegetation transpiration ranged from-16% to 9% and-100% to 15%, respectively, in response to extremes of doubled and zero LAI, respectively. There was a negative feedback between vegetation and the volumetric unfrozen water content at 0.2 m through changing evapotranspiration. The simulation results of soil temperature and moisture suggest that better vegetation conditions are conducive to maintaining the thermal stability of the underlying permafrost, and the advanced initial thawing time and increasing thawing rate of soil ice with the increase in the LAI may have a great influence on the timing and magnitude of supra-permafrost groundwater. This study quantifies the impact of vegetation change on surface and subsurface hydrothermal processes and provides a basic understanding for evaluating the impact of vegetation degradation on the water-heat exchange in permafrost regions under climate change. 展开更多
关键词 PERMAFROST Simultaneous heat and water model Leaf area index water-Heat exchange Thermal-moisture dynamics
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Preparation of New Cementitious System using Fly Ash and Dehydrated Autoclaved Aerated Concrete 被引量:3
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作者 水中和 LU Jianxin +2 位作者 TIAN Sufang SHEN Peiliang DING Sha 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第4期726-732,共7页
We experimentally studied the interaction between pozzolanic material(fly ash) and dehydrated autoclaved aerated concrete(DAAC). The DAAC powder was obtained by grinding aerated concrete waste to particles fi ner ... We experimentally studied the interaction between pozzolanic material(fly ash) and dehydrated autoclaved aerated concrete(DAAC). The DAAC powder was obtained by grinding aerated concrete waste to particles fi ner than 75μm and was then heated to temperatures up to 900 ℃. New cementitious material was prepared by proportioning fly ash and DAAC, named as AF. X-ray diffraction(XRD) was employed to identify the crystalline phases of DAAC before and after rehydration. The hydration process of AF was analyzed by the heat of hydration and non-evaporable water content(Wn). The experimental results show that the highest reactivity of DAAC can be obtained by calcining the powder at 700 ℃ and the dehydrated products are mainly β-C2 S and CaO. The cumulative heat of hydration and Wn was found to be strongly dependent on the replacement level of fl y ash, increasing the replacement level of fl y ash lowered them in AF. The strength contribution rates on pozzolanic effect of fl y ash in AF are always negative, showing a contrary tendency of that of cement-fl y ash system. 展开更多
关键词 dehydrated autoclaved aerated concrete pozzolanic reaction heat of hydration nonevaporable water content strength contribution rate
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Finite element simulation of three-dimensional temperature field in underwater welding 被引量:1
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作者 刘习文 王国荣 +1 位作者 石永华 钟继光 《China Welding》 EI CAS 2007年第2期59-65,共7页
Mathematical models of three-dimensional temperature fields in underwater welding with moving heat sources are built. Double ellipsoid Gauss model is proposed as heat sources models. Several factors which affect the t... Mathematical models of three-dimensional temperature fields in underwater welding with moving heat sources are built. Double ellipsoid Gauss model is proposed as heat sources models. Several factors which affect the temperature fields of underwater welding are analyzed. Water has little influence on thermal efftciency. Water convection coefftcient varies with the temperature difference between the water and the workpiece , and water convection makes molten pool freeze quickly. With the increase of water depth, the dimensions of heat sources model should be reduced as arc shrinks. Finite element technology is used to solve mathematical models. ANSYS software is used as finite element tool, and ANSYS Parametric Design Language is used to develop subprograms for loading the moving heat sources and the various convection coefftcients. Experiment results show that computational results by using double ellipsoid Gauss heat sources model accord well with the experimental results. 展开更多
关键词 underwater welding temperature fields finite element method double ellipsoid Gauss heat sources model water convection
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Recent Progresses on Optimal Design of Heat Integrated Water Allocation Network
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作者 Zhang Chijin Ren Congjing +3 位作者 Liao Zuwei Sun Jingyuan Wang Jingdai Yang Yongrong 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2021年第3期69-75,共7页
Energy integration and mass integration are important approaches to achieve energy saving and emission reduction in the process industry.Generally,the methods can be classified into two groups,viz.:conceptual design m... Energy integration and mass integration are important approaches to achieve energy saving and emission reduction in the process industry.Generally,the methods can be classified into two groups,viz.:conceptual design methods and mathematical programming methods.The former includes mainly graphical methods based on pinch technology that is operated easily.A feasible solution can be quickly obtained.Conceptual design methods are sequential in nature including two steps,namely:targeting and designing.The latter is based on superstructure optimization,and corresponding algorithm is adopted to solve the model.The trade-offs and connections among the entire network can be established and explored.Multiple factors can be considered and optimized simultaneously by mathematical programming methods.This paper describes the synthesis of heat integrated water allocation networks(HIWAN)based on both conceptual design methods and mathematical programming methods systematically.In addition,the characteristics and shortcomings of the existing research methods are summarized,and the future research direction is prospected. 展开更多
关键词 heat integrated water allocation network conceptual design mathematical programming
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Cool water brought by upwelling in the Sanya Bay benefits corals in the background of global warming
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作者 YANG Dingtian 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第3期14-19,共6页
It has been reported that global warming has negative effects on coral ecosystems in the past 50 years and the effects vary in different ocean environment. In order to make clear the coral reef status in the backgroun... It has been reported that global warming has negative effects on coral ecosystems in the past 50 years and the effects vary in different ocean environment. In order to make clear the coral reef status in the background of global warming along the south coast of Hainan Island of China, satellite and in situ data are used to retrieve the information of the coral reef status and surrounding environmental factors. The results show that cool water induced by upwelling along the south coast of Hainan Island is found in the area every summer month, especially in the relatively strong El Ni?o years(2002–2003 and 2005). From the NOAA satellite data, degree heating week(DHW) index does not exceed 3 in Sanya Bay even in the relatively strong El Ni?o years. By comparison of a coral reef growth rate in the Sanya Bay with respect to El Ni?o events from 1957 to 2000, coral's growth rate is relatively greater during 1972, 1991–1994 and 1998 El Ni?o event. By analyzing the environmental factors, it is found that the cool water induced by upwelling may be the main reason for protecting corals from global warming effects. 展开更多
关键词 cool water upwelling corals degree heating week Sanya Bay
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Autonomous Changes in the Concentration of Water Vapor Drive Climate Change
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作者 William A. Van Brunt 《Atmospheric and Climate Sciences》 2020年第4期443-508,共66页
When compared to the average annual global temperature record from 1880, no published climate model posited on the assumption that the increasing concentration of atmospheric carbon dioxide is the driver of climate ch... When compared to the average annual global temperature record from 1880, no published climate model posited on the assumption that the increasing concentration of atmospheric carbon dioxide is the driver of climate change can accurately replicate the significant variability in the annual temperature record. Therefore, new principles of atmospheric physics are developed for determining changes in the average annual global temperature based on changes in the average atmospheric concentration of water vapor. These new principles prove that: 1) Changes in average global temperature are not driven by changes in the concentration of carbon dioxide;2) Instead, autonomous changes in the concentration of water vapor, <span style="white-space:nowrap;">Δ</span>TPW, drive changes in water vapor heating, thus, the average global temperature, <span style="white-space:nowrap;">Δ</span>T<sub>Avg</sub>, in accordance with this principle, <span style="white-space:normal;"><span style="white-space:nowrap;">Δ</span>T</span><span style="white-space:normal;"><sub>Avg</sub>=0.4<span style="white-space:normal;"><span style="white-space:nowrap;">Δ</span>TPW </span></span>the average accuracy of which is ±0.14%, when compared to the variable annual, 1880-2019, temperature record;3) Changes in the concentration of water vapor and changes in water vapor heating are not a feedback response to changes in the concentration of CO<sub>2</sub>;4) Rather, increases in water vapor heating and increases in the concentration of water vapor drive each other in an autonomous positive feedback loop;5) This feedback loop can be brought to a halt if the average global rate of precipitation can be brought into balance with the average global rate of evaporation and maintained there;and, 6) The recent increases in average global temperature can be reversed, if average global precipitation can be increased sufficiently to slightly exceed the average rate of evaporation. 展开更多
关键词 Carbon Dioxide Climate Change water Vapor Global Warming DRIVER Average Global Temperature Change in Concentration water Vapor water Vapor heating
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Erratum to “Autonomous Changes in the Concentration of Water Vapor Drive Climate Change” [Atmospheric and Climate Sciences 10 (2020) 443-508]
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作者 William Van Brunt 《Atmospheric and Climate Sciences》 2021年第3期535-546,共12页
<p> A. <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Changes </span></span></span><... <p> A. <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Changes </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in</span></span></span><span><span><span style="font-family:" color:black;"=""><span style="font-family:Verdana;"> average global temperature are not driven by changes in the concentration of carbon dioxide;</span></span></span></span> </p> <p> <span style="font-family:Verdana;">B. </span><span style="font-family:Verdana;">Instead, autonomous changes in the concentration of water vapor, </span><span style="font-family:Verdana;">Δ</span><span style="font-family:Verdana;">TPW, </span><span color:black;"=""><span style="font-family:Verdana;">drive changes in water vapor heating, thus, </span><span style="background:#C00000;font-family:Verdana;">changes in</span><span style="font-family:Verdana;"> the average global temperature, </span></span><span style="font-family:Verdana;">Δ</span><span style="font-family:Verdana;"><i>T</i></span><span style="font-family:Verdana;"><sub>Avg</sub></span><span color:black;"=""><span style="font-family:Verdana;">, </span><span style="background:#C00000;font-family:Verdana;">in deg. Celsius are calculated</span><span style="font-family:Verdana;"> in accordance with this principle,</span></span> </p> <p style="text-align:center;margin-left:10pt;"> <span><span><span style="font-family:" color:black;"=""><span style="font-family:Verdana;"></span><img src="Edit_6e770969-a7c9-4192-a6ad-03de906a4d65.bmp" alt="" /><br /> </span></span></span> </p> <p align="center" style="margin-left:10.0pt;text-align:center;"> <span><span><span style="font-family:;" "=""><span></span></span></span><span><span><span style="font-family:" color:black;"=""></span></span></span></span> </p> <p> <span><span><span style="font-family:" color:black;background:#c00000;"=""><span style="font-family:Verdana;">measured in kg<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"="">·</span></span>m</span><sup><span style="font-family:Verdana;"><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">-</span>2</span></sup><span style="font-family:Verdana;">,</span></span></span></span><span><span><span style="font-family:" color:black;"=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the average accuracy of which is ±0.14%, when compared to the variable annual, 1880 </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:" color:black;"=""><span style="font-family:Verdana;"> 2019, </span><span style="background:#C00000;font-family:Verdana;">average global </span><span style="font-family:Verdana;">temperature record;</span></span></span></span> </p> 展开更多
关键词 Carbon Dioxide Climate Change water Vapor Global Warming DRIVER Average Global Temperature Change in Concentration water Vapor water Vapor heating
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PARAMETERS OF WATER CIRCULATION NETWORK FOR A DISTRICT HEATING AND COOLING SYSTEM
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作者 Fu, Lin Pan, Jihong Jiang, Yi 《Journal of Hydrodynamics》 SCIE EI CSCD 2000年第1期87-95,共9页
In a district heating and cooling system, i.e. Beijing combined heating cooling and power (CHCP) system studied here, the high temperature water generated by two cogeneration plants circulates through a network betwee... In a district heating and cooling system, i.e. Beijing combined heating cooling and power (CHCP) system studied here, the high temperature water generated by two cogeneration plants circulates through a network between the plants and heat substations. At heat substations, the supply water of high temperature from the network drives absorption chillers for air-conditioning in summer and meets space heating demands in winter or domestic hot water demands by heat exchangers in the whole year. The parameters, i.e. supply/return water temperatures in the network, have a great impact on primary energy consumption (PEC) of the absorption chillers, circulation pumps and domestic hot water (DHW), which is studied in this paper. 展开更多
关键词 Boiler circulation Energy utilization Hot water heating Parameter estimation water cooling systems
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Arrangement of Multirow Solar Collector Array on Limited Roof Width
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作者 PU Shaoxuan XIA Chaofeng 《Journal of Northeast Agricultural University(English Edition)》 CAS 2010年第4期76-82,共7页
At the limited roof north-south (N-S) width of a building, for the array with multirow collectors based on no shading at winter solstice noon and sloped at latitude, this paper studied the shading and the radiant en... At the limited roof north-south (N-S) width of a building, for the array with multirow collectors based on no shading at winter solstice noon and sloped at latitude, this paper studied the shading and the radiant energy striking on solar collector array. Based on Kunming solar radiation data, the annual and monthly solar radiant energy striking on multi-array collectors was analyzed and estimated, from no shading to partial shading by adding 1-3 collector row, at the slopes of 10°, 15°, 20°, 25°, 30°, 35° and 40°, respectively. The results showed that properly increasing the row number by reducing the slope of collectors was reasonable in order to get more annual radiant energy. Adding 1 row at 10° of slope was economical for Kunming, based on the 5-row array at 25°. And adding collector row by 20% at 10° of slope could increase the radiant energy striking on the array by 19%. 展开更多
关键词 limited roof width solar water heating system multirow collector array optimizing design
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The characteristics of sea fog with different airflow over the Huanghai Sea in boreal spring 被引量:6
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作者 HUANG Jian WANG Xin +3 位作者 ZHOU Wen HUANG Huijun WANG Dongxiao ZHOU Faxiu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2010年第4期3-12,共10页
Using the observations from ICOADS datasets and contemporaneous NCEP/NCAR reanalysis datasets during 1960-2002,the study classifies the airflows in favor of sea fog over the Huanghai (Yellow) Sea in boreal spring (... Using the observations from ICOADS datasets and contemporaneous NCEP/NCAR reanalysis datasets during 1960-2002,the study classifies the airflows in favor of sea fog over the Huanghai (Yellow) Sea in boreal spring (April-May) with the method of trajectory analysis,and analyzes the changes of proportions of warm and cold sea fogs along different paths of airflow.According to the heat balance equation,we investigate the relationships between the marine meteorological conditions and the proportion of warm and cold sea fog along different airflow paths.The major results are summarized as follows.(1) Sea fogs over the Huanghai Sea in spring are not only warm fog but also cold fog.The proportion of warm fog only accounts for 44% in April,while increases as high as 57% in May.(2) Four primary airflow paths leading to spring sea fog are identified.They are originated from the northwest,east,southeast and southwest of the Huanghai Sea,respectively.The occurrence ratios of the warm sea fog along the east and southeast airflow paths are high of 55% and 70%,while these along the southwest and northwest airflow paths are merely 17.9% and 50%.(3) The key physical processes governing the warm/cold sea fog are heat advection transport,longwave radiation cooling at fog top,solar shortwave warming and latent heat flux between airsea interfaces.(4) The characteristics of sea fog along the four airflow paths relate closely to the conditions of water vapor advection,and the vertical distribution of relative humidity. 展开更多
关键词 spring sea fog over the Huanghai Sea airflow paths water vapor flux heat advection vertical distribution of water vapor
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Numerical Experiments for the influence of the Transition Zone Migration on Summer Climate in North China 被引量:1
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作者 郑维忠 倪允琪 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1999年第3期367-377,共11页
As the position of the transition zone changes obviously, that is, as the transition zone migrates to the north or the south from present position, it affects water or heat balance between the land and the atmosphere ... As the position of the transition zone changes obviously, that is, as the transition zone migrates to the north or the south from present position, it affects water or heat balance between the land and the atmosphere in a considerable degree and has a profound influence on climate in North China. The experiment results in this paper indicate whether in the dry case or in the wet case of the large-scale climatological background field, the surface air temperature in a wide range of the transition zone migration and its surrounding decreases as the transition zone migrates northward. Moreover, the net upward fluxes of the surface long wave radiation and the sensible heat decrease, and the evaporation to the atmosphere increases. As the transition zone migrates southward, the results are opposite. This kind of significant thermal forcing between the land and the atmosphere can excite secondary circulation or circulation cells, which interact with the large-scale circulation systems, changing the atmospheric motion, affecting the water vapor transportation and consequently having an effect on the precipitation. 展开更多
关键词 Transition zone migration water and heat balance Climate in North China Numerical simulation
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