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Energy, Exergy and Thermoeconomics Analysis of Water Chiller Cooler for Gas Turbines Intake Air Cooling 被引量:1
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作者 Galal Mohammed Zaki Rahim Kadhim Jassim Majed Moalla Alhazmy 《Smart Grid and Renewable Energy》 2011年第3期190-205,共16页
Gas turbine (GT) power plants operating in arid climates suffer a decrease in output power during the hot summer months because of the high specific volume of air drawn by the compressor. Cooling the air intake to the... Gas turbine (GT) power plants operating in arid climates suffer a decrease in output power during the hot summer months because of the high specific volume of air drawn by the compressor. Cooling the air intake to the compressor has been widely used to mitigate this shortcoming. Energy and exergy analysis of a GT Brayton cycle coupled to a refrigeration air cooling unit shows a promise for increasing the output power with a little decrease in thermal efficiency. A thermo-economics algorithm is developed to estimate the economic feasibility of the cooling system. The analysis is applied to an open cycle, HITACHI-FS7001B GT plant at the industrial city of Yanbu (Latitude 24o 05” N and longitude 38o E) by the Red Sea in the Kingdom of Saudi Arabia. Result show that the enhancement in output power depends on the degree of chilling the air intake to the compressor (a 12 - 22 K decrease is achieved). For this case study, maximum power gain ratio (PGR) is 15.46% (average of 12.25%), at an insignificant decrease in thermal efficiency. The second law analysis show that the exergetic power gain ratio drops to an average 8.5%. The cost of adding the air cooling system is also investigated and a cost function is derived that incorporates time-dependent meteorological data, operation characteristics of the GT and the air intake cooling system and other relevant parameters such as interest rate, lifetime, and operation and maintenance costs. The profit of adding the air cooling system is calculated for different electricity tariff. 展开更多
关键词 Gas Turbine EXERGY Analysis Power BOOSTING Hot Climate air cooling water CHILLER
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Optimization of rhizosphere cooling airflow for microclimate regulation and its effects on lettuce growth in plant factory 被引量:3
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作者 LI Kun FANG Hui +1 位作者 ZOU Zhi-rong CHENG Rui-feng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第10期2680-2695,共16页
In plant factories,the plant microclimate is affected by the control system,plant physiological activities and aerodynamic characteristics of leaves,which often leads to poor ventilation uniformity,suboptimal environm... In plant factories,the plant microclimate is affected by the control system,plant physiological activities and aerodynamic characteristics of leaves,which often leads to poor ventilation uniformity,suboptimal environmental conditions and inefficient air conditioning.In this study,interlayer cool airflow(ILCA)was used to introduce room air into plants’internal canopy through vent holes in cultivation boards and air layer between cultivation boards and nutrient solution surface(interlayer).By using optimal operating parameters at a room temperature of 28℃,the ILCA system achieved similar cooling effects in the absence of a conventional air conditioning system and achieved an energy saving of 50.8% while bringing about positive microclimate change in the interlayer and nutrient solution.This resulted in significantly reduced root growth by 41.7% without a negative influence on lettuce crop yield.Future development in this precise microclimate control method is predicted to replace the conventional cooling(air conditioning)systems for crop production in plant factories. 展开更多
关键词 air movement environmental control MICROCLIMATE water cooling root and shoot growth
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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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Water, land, and energy use efficiencies and financial evaluation of air conditioner cooled greenhouses based on field experiments
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作者 Ibtihal AL-MANTHRIA Abdulrahim M AL-ISMAILIA +2 位作者 Hemesiri KOTAGAMAB Mumtaz KHANC L H Janitha JEEWANTHAD 《Journal of Arid Land》 SCIE CSCD 2021年第4期375-387,共13页
High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial asp... High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial aspects of the AC-cooled greenhouse as compared to the evaporative cooled(EV-cooled)greenhouse in winter and summer seasons.Two quonset single-span prototype greenhouses were built in the Agriculture Experiment Station of Sultan Qaboos University,Oman,with dimensions of 6.0 m long and 3.0 m wide.The AC-cooled greenhouse was covered by a rockwool insulated polyethylene plastic sheet and light emitting diodes(LED)lights were used as a source of light,while the EV-cooled greenhouse was covered by a transparent polyethylene sheet and sunlight was used as light source.Three cultivars of high-value lettuce were grown for experimentation.To evaluate the technical efficiency of greenhouse performance,we conducted measures on land use efficiency(LUE),water use efficiency(WUE),gross water use efficiency(GWUE)and energy use efficiency(EUE).Financial analysis was conducted to compare the profitability of both greenhouses.The results showed that the LUE in winter were 10.10 and 14.50 kg/m^(2) for the AC-and EV-cooled greenhouses,respectively.However,the values reduced near to 6.80 kg/m^(2) in both greenhouses in summer.The WUE of the AC-cooled greenhouse was higher than that of the EV-cooled greenhouse by 3.8%in winter and 26.8%in summer.The GWUE was used to measure the total yield to the total greenhouse water consumption including irrigation and cooling water;it was higher in the AC-cooled greenhouse than in the EV-cooled greenhouse in both summer and winter seasons by almost 98.0%–99.4%.The EUE in the EV-cooled greenhouse was higher in both seasons.Financial analysis showed that in winter,gross return,net return and benefit-to-cost ratio were better in the EVcooled greenhouse,while in summer,those were higher in the AC-cooled greenhouse.The values of internal rate of return in the AC-and EV-cooled greenhouses were 63.4%and 129.3%,respectively.In both greenhouses,lettuce investment was highly sensitive to changes in price,yield and energy cost.The financial performance of the AC-cooled greenhouse in summer was better than that of the EV-cooled greenhouse and the pattern was opposite in winter.Finally,more studies on the optimum LED light intensity for any particular crop have to be conducted over different growing seasons in order to enhance the yield quantity and quality of crop. 展开更多
关键词 land use efficiency energy use efficiency water use efficiency gross water use efficiency financial evaluation air conditioner cooled greenhouse evaporative cooled greenhouse
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Application of Air-cooled Blast Furnace Slag Aggregates as Replacement of Natural Aggregates in Cement-based Materials:A Study on Water Absorption Property 被引量:1
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作者 王爱国 liu peng +3 位作者 liu kaiwei li yan zhang gaozhan 孙道胜 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第2期445-451,共7页
The influence of air-cooled blast furnace slag aggregates as replacement of natural aggregates on the water absorption of concrete and mortar was studied, and the mechanism was analyzed. The interface between aggregat... The influence of air-cooled blast furnace slag aggregates as replacement of natural aggregates on the water absorption of concrete and mortar was studied, and the mechanism was analyzed. The interface between aggregate and matrix in concrete was analyzed by using a micro-hardness tester, a laser confocal microscope and a scanning electron microscope with backscattered electron image mode. The pore structure of mortar matrixes under different curing conditions was investigated by mercury intrusion porosimetry. The results showed that when natural aggregates were replaced with air-cooled blast furnace slag aggregates in mortar or concrete, the content of the capillary pore in the mortar matrix was reduced and the interfacial structure between aggregate and matrix was improved, resulting in the lower water absorption of mortar or concrete. Compared to the concrete made with crushed limestone and natural river sand, the initial absorption coefficient, the secondary absorption coefficient and the water absorption capacity through the surface for 7 d of the concrete made from crushed air-cooled blast furnace slag and air-cooled blast furnace slag sand were reduced by 48.9%, 52.8%, and 46.5%, respectively. 展开更多
关键词 air-cooled blast furnace slag aggregate cement-based materials water absorption coefficient interface structure
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Multiperiod optimization of cooling water system with flexible topology network
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作者 Bo Liu Ruimei Zhang +3 位作者 Ye Liu Yufei Wang Ali Almansoori Xiao Feng 《Green Chemical Engineering》 EI CSCD 2024年第4期461-472,共12页
Cooling water systems(CWSs)are extensively utilized in various industries to eliminate the excess heat and converse energy.Studies on CWSs mainly concentrated on finding the optimal cooler network structure.In additio... Cooling water systems(CWSs)are extensively utilized in various industries to eliminate the excess heat and converse energy.Studies on CWSs mainly concentrated on finding the optimal cooler network structure.In addition,some works also considered the optimal design under varied operation conditions.However,in these works,once the optimal design of the cooler's network is determined,its arrangement remains fixed and cannot be adapted to accommodate diverse operating conditions.In this work,a flexible topology network concept is proposed to make the adjustment of network structure possible under different operation conditions.The CWS with integrated air cooler and flexible topology network has better overall performance,represented by a mixed integer nonlinear programming(MINLP)model that require advanced tools such as GAMS software.Case studies revealed that the proposed methodology can realize better energy-saving performance,and improve the economic performance under varied operation conditions.The impact of critical flexible nodes on system configuration and economy is achieved by sensitivity analysis. 展开更多
关键词 cooling water systems Flexible network Multiperiod optimization air cooler
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Effect of cooling conditions on corrosion resistance of friction stir welded 2219-T62 aluminum alloy thick plate joint 被引量:11
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作者 Wei-feng XU Jun MA +2 位作者 Miao WANG Hong-jian LU Yu-xuan LUO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第6期1491-1499,共9页
Friction stir welding (FSW) with water cooling and air cooling was used to weld 2219-T62 aluminum alloy joints with a thickness of 20 mm. The effect of cooling conditions on the corrosion resistance of joints in 3.5% ... Friction stir welding (FSW) with water cooling and air cooling was used to weld 2219-T62 aluminum alloy joints with a thickness of 20 mm. The effect of cooling conditions on the corrosion resistance of joints in 3.5% NaCl solution was investigated using the open circuit potential (OCP), the potentiodynamic polarization, and the corrosion morphology after immersing for different time. And the precipitates distribution was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results reveal that the weld nugget zone (WNZ) owning positive potential, lower corrosion current density and fine and uniform precipitates, is much more difficult to corrode than the heat affected zone (HAZ) and the base metal (BM). Compared with air-cooled joint, the water-cooled joint has better corrosion resistance. In addition, the results of microstructure observation show that the potential, distribution and size of second phase particles determine the corrosion resistance of FSW AA2219 alloy joints in chlorine-contained solution. 展开更多
关键词 friction stir welding aluminum alloy air cooling water cooling corrosion resistance second phase particles
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Profile distribution and seasonal dynamics of water-extractable carbohydrate in soils under mixed broad-leaved Korean pine forest on Changbai Mountain 被引量:7
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作者 ZHAO Shan-shan SUN Jin-bing CUI Xiao-yang 《Journal of Forestry Research》 SCIE CAS CSCD 2013年第3期509-514,共6页
Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable car- bohydrate i... Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable car- bohydrate is thought related to soil carbon sequestration due to the asso- ciation with soil aggregation. In a temperate forest region of northeast China, Changbai Mountain, we investigated the abundance, spatial dis- tribution, and seasonal dynamics of cool and hot-water extractable car- bohydrate in soils under mixed broad-leaved Korean pine forest. The concentrations of cool-water extractable carbohydrate (CWECH) in three soil layers (0-5, 5-10, 10-20 cm) ranged from 4.1 to 193.3 g.kg-1 dry soil, decreasing rapidly with soil depth. On an annual average, the CWECH concentrations in soils at depths of 5-10 and 10-20 cm were 54.2% and 24.0%, respectively, of that in the 0-5 cm soil layer. CWECH showed distinct seasonal dynamics with the highest concentrations in early spring, lowest in summer, and increasing concentrations in autumn. Hot-water extractable carbohydrate (HWECH) concentrations in three soil layers ranged from 121.4 to 2026.2 g.kgq dry soil, which were about one order of magnitude higher than CWECH. The abundance of HWECH was even more profile-dependent than CWECH, and decreased more rapidly with soil depth. On an annual average, the HWECH concentration in soils 10-20 cm deep was about one order of magnitude lower than that in the top 0-5 cm soil. The seasonality of HWECH roughly tracked that of CWECH but with seasonal fluctuations of smaller amplitude. The car- bohydrate concentrations in cool/hot water extracts of soil were positively correlated with UV254 and UV2s0 of the same solution, which has implications for predicting the leaching loss of water soluble organic carbon. 展开更多
关键词 forest soil cool-water extractable carbohydrate hot-waterextractable carbohydrate profile distribution seasonal dynamics
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Cooling System Design and Thermal Analysis of Modular Stator Hybrid Excitation Synchronous Motor 被引量:1
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作者 Shengnan Wu Daquan Hao Wenming Tong 《CES Transactions on Electrical Machines and Systems》 CSCD 2022年第3期241-251,共11页
Hybrid excitation synchronous motor has the advantages of uniform and adjustable electromagnetic field, wide speed range and high power density. It has broad application prospects in new energy electric vehicles, wind... Hybrid excitation synchronous motor has the advantages of uniform and adjustable electromagnetic field, wide speed range and high power density. It has broad application prospects in new energy electric vehicles, wind power generation and other fields. This paper introduces the basic structure of hybrid excitation motor with modular stator, and analyzes the operation principle of hybrid excitation motor. The cooling structure of the water-cooled plate is designed, and the effects of the thickness of the water-cooled plate and the number of water channels in the water-cooled plate on the heat dissipation capacity of the water-cooled plate are analyzed by theoretical and computational fluid dynamics methods. The effects of different water cooling plate structures on water velocity, pressure drop, water pump power consumption and heat dissipation capacity were compared and analyzed. The influence of different inlet flow velocity on the maximum temperature rise of each part of the motor is analyzed, and the temperature of each part of the motor under the optimal water flow is analyzed. The influence of the traditional spiral water jacket cooling structure and the water-cooled plate cooling structure on the maximum temperature rise of the motor components is compared and analyzed. The results show that the water-cooled plate cooling structure is more suitable for the modular stator motor studied in this paper. Based on the water-cooled plate cooling structure, the air-water composite cooling structure is designed, and the effects of the air-water composite cooling structure and the water-cooled plate cooling structure on the maximum temperature rise of each component of the motor are compared and analyzed. The results show that the maximum temperature rise of each component of the motor is reduced under the air-water composite cooling structure. 展开更多
关键词 Hybrid excitation synchronous motor cooling structure of the water-cooled plate The heat dissipation capacity of the water-cooled plate The maximum temperature rise of each part air water composite cooling structure
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The Influence of Drying Temperature and Extraction Methods on a-Mangostin in Mangosteen Pericarp
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作者 W. Satong-aun R. Assawarachan A. Noomhorm 《Journal of Food Science and Engineering》 2011年第2期85-92,共8页
The effects of drying temperature and extraction methods on α-mangostin content in mangosteen pericarp (Garcinia mangostana L.) powder were investigated. In the first part of experiment suitable drying temperature ... The effects of drying temperature and extraction methods on α-mangostin content in mangosteen pericarp (Garcinia mangostana L.) powder were investigated. In the first part of experiment suitable drying temperature for retention α-mangostin content was determined. Three levels of drying temperatures (55, 65 and 75 ℃) were used in this study. The drying rates were increased with drying temperature. Room temperature extraction method was performed to investigate the effect of drying temperature on retention α-mangostin content in mangosteen pericarp. The α-mangostin content extracted at three different drying temperatures (55, 65 and 75 ℃) was 35.98 ± 0.49%, 40.32 ± 0.24%, and 37.79±0.34% w/w, respectively. The results showed that the suitable temperature for drying mangosteen pericarp was 65 ℃ that gave the highest of α-mangostin content. The second part of experiment was the comparison between extraction methods, such as shaking water bath extraction (SWE), soxhlet extraction (SE) and microwave-assisted extraction (MAE). The results show that MAE gave the highest extraction rate and α-mangostin content as compare to SWE and SE. The α-mangostin content extraction from SWE, SE and MAE are 45.83 ± 0.02, 34.82± 0.17 and 49.79 ± 0.15% w/w of crude extract, respectively. 展开更多
关键词 Mangosteen pericarp alpha-mangostin hot air drying room temperature extraction water bath extraction soxhletextraction microwave-assisted extraction.
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Thermodynamic Simulation of CCP in Air-Cooled Heat Pump Unit with HFCs and CO<sub>2</sub>Trans-Critical 被引量:2
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作者 Feihu Chen Shuguang Liao Guangcai Gong 《Journal of Power and Energy Engineering》 2018年第9期141-164,共24页
The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit ... The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit is about 1 kW, and the work refrigerant is R22/R407C/R410A/CO2. The MATLAB/SIMULINK software was employed to build the simulation model. The thermodynamic simulation model is significant for the optimization of parameters of the unit, such as condensation and evaporation temperature and mass flow of the sanitary hot water and size of hot water storage tank. The COP of the CCP of R410A system is about 3% - 5% higher than the CCP of the R22 system, while CCP of the R407C system is a little lower than the CCP of R22 system. And the CCP of CO2 trans-critical system has advantage in the hot supply mode. The simulation method provided a theoretical reference for developing the production of CCP with substitute refrigerant R407C/R410A/CO2. 展开更多
关键词 air-cooled Heat Pump Unit Compound Condensation Process (CCP) Exergy Analysis Method Sanitary Hot water MATLAB/SIMULINK Software Fluorine SUBSTITUTE REFRIGERANT R407C/R410A Natural REFRIGERANT CO2
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数据中心冷却系统研究及应用进展 被引量:1
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作者 周峰 谷文龙 +1 位作者 马国远 晏祥慧 《制冷与空调》 2024年第2期63-71,共9页
为加速实现数据中心节能降耗的目标,在合理、高效、最大化地利用自然冷源的同时,更不能忽视机械制冷系统本身能效的提升。加强自然冷却与机械制冷的协同,降低数据中心PUE,充分发挥安全稳定、高效运行的数据中心冷却系统自身能效至关重... 为加速实现数据中心节能降耗的目标,在合理、高效、最大化地利用自然冷源的同时,更不能忽视机械制冷系统本身能效的提升。加强自然冷却与机械制冷的协同,降低数据中心PUE,充分发挥安全稳定、高效运行的数据中心冷却系统自身能效至关重要。本文通过对气流组织、供/回水温度和冷却系统部件及形式3个方面的研究梳理,总结分析数据中心冷却系统节能提效有关技术研究与应用进展,从而为绿色、高效数据中心冷却系统的研发提供参考和借鉴。 展开更多
关键词 数据中心 冷却系统 气流组织 供回水温度 部件及形式
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石墨炉原子吸收测定间接空冷机组循环水中的痕量铝
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作者 星成霞 李永立 +1 位作者 顾融融 胡远翔 《工业水处理》 CAS CSCD 北大核心 2024年第11期167-171,共5页
采用石墨炉原子吸收测定SCAL型间接空冷机组循环水中的痕量铝,从石墨炉工作参数、基体改进剂、试剂空白、水样前处理等方面进行了实验条件优选。实验结果表明:石墨炉灰化温度、原子化温度分别为700℃和2 700℃,不加基体改进剂条件下,铝... 采用石墨炉原子吸收测定SCAL型间接空冷机组循环水中的痕量铝,从石墨炉工作参数、基体改进剂、试剂空白、水样前处理等方面进行了实验条件优选。实验结果表明:石墨炉灰化温度、原子化温度分别为700℃和2 700℃,不加基体改进剂条件下,铝离子标液质量浓度在0~20μg/L范围内标准曲线线性相关系数可达到0.999 8,相对标准偏差小于10%,检测下限为0.5μg/L。采用水样酸化静置1 h后直接测定并与标准加热消解法测定值进行了对比,相对误差小于5.0%,空白值小于0.5μg/L,有效解决了加热消解法空白值高的问题,提高了间接空冷机组循环水中小于10μg/L痕量铝测定的准确性。 展开更多
关键词 石墨炉原子吸收分光光度法 间接空冷机组循环水 痕量铝 基体改进剂 空白值 水样前处理
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联合收获机发动机风冷系统优化设计 被引量:1
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作者 刘晓霞 李耀明 +3 位作者 王法政 李顾鹏 杜拓 夏圣博 《农机化研究》 北大核心 2024年第5期222-227,共6页
为了减少联合收获机收获过程中水箱“开锅”现象的发生,延长收获机的无故障工作时长,对4LXZ-8F型联合收获机的发动机风冷系统散热量进行了计算,并基于计算结果对防尘罩、散热器进行了优化设计,对冷却风扇进行了匹配选型。利用SolidWork... 为了减少联合收获机收获过程中水箱“开锅”现象的发生,延长收获机的无故障工作时长,对4LXZ-8F型联合收获机的发动机风冷系统散热量进行了计算,并基于计算结果对防尘罩、散热器进行了优化设计,对冷却风扇进行了匹配选型。利用SolidWorks对优化前后风冷系统进行了三维建模,利用Fluent软件对发动机风冷系统优化前和优化后散热器散热性能分别进行仿真分析。仿真结果表明:优化前的冷却水入口温度为90℃,出口温度为72.3℃,进出口温差为17.7℃;优化后的冷却水入口温度为90℃,出口温度为71.1℃,进出口温差为18.9℃,表明优化后散热器散热性能提升了6.78%。研究成果可为提高发动机风冷系统的散热性能,延长无故障收获时长提供理论指导。 展开更多
关键词 联合收获机 水箱“开锅” 风冷系统 结构优化 仿真分析
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Performance evaluation of an improved biomass-fired cogeneration system simultaneously using extraction steam, cooling water, and feedwater for heating
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作者 Peiyuan PAN Yunyun WU Heng CHEN 《Frontiers in Energy》 SCIE CSCD 2022年第2期321-335,共15页
An advanced cogeneration system based on biomass direct combustion was developed and its feasibility was demonstrated. In place of the traditional single heat source (extraction steam), the extraction steam from the t... An advanced cogeneration system based on biomass direct combustion was developed and its feasibility was demonstrated. In place of the traditional single heat source (extraction steam), the extraction steam from the turbine, the cooling water from the plant condenser, and the low-pressure feedwater from the feedwater preheating system were collectively used for producing district heat in the new scheme. Hence, a remarkable energy-saving effect could be achieved, improving the overall efficiency of the cogeneration system. The thermodynamic and economic performance of the novel system was examined when taking a 35 MW biomass-fired cogeneration unit for case study. Once the biomass feed rate and net thermal production remain constant, an increment of 1.36 MW can be expected in the net electric production, because of the recommended upgrading. Consequently, the total system efficiency and effective electrical efficiency augmented by 1.23 and 1.50 percentage points. The inherent mechanism of performance enhancement was investigated from the energy and exergy aspects. The economic study indicates that the dynamic payback period of the retrofitting project is merely 1.20 years, with a net present value of 5796.0 k$. In conclusion, the proposed concept is validated to be advantageous and profitable. 展开更多
关键词 biomass-fired cogeneration district heat production system absorption heat pump extraction steam cooling water low-pressure feedwater
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自然通风湿式冷却塔节水方案的数值研究
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作者 杨岑 宋小军 +3 位作者 赵顺安 李陆军 宋志勇 黄春花 《中国水利水电科学研究院学报(中英文)》 北大核心 2024年第4期368-376,共9页
为降低自然通风湿式冷却塔的耗水量,本文采用一种可用于回收其蒸发损失的空气冷凝器结构,并通过数值模拟方法对其节水特性展开研究。首先基于空气运动控制方程和水蒸气冷凝模型,建立了用于分析空气冷凝器节水特性的数学模型,其次分析了... 为降低自然通风湿式冷却塔的耗水量,本文采用一种可用于回收其蒸发损失的空气冷凝器结构,并通过数值模拟方法对其节水特性展开研究。首先基于空气运动控制方程和水蒸气冷凝模型,建立了用于分析空气冷凝器节水特性的数学模型,其次分析了冷却空气流速、空气冷凝器的结构尺寸和材质等因素对该冷凝器节水特性的影响。研究结果表明:空气冷凝器的单位面积节水量随着冷却空气流速以及冷凝器宽度的增大而增大,但随着冷凝器长度和高度的增大而减小;空气冷凝器的材质和壁厚对其单位面积节水量没有显著影响,空气冷凝器可采用重量轻和成本低的薄壁PVC来加工制造。 展开更多
关键词 湿式冷却塔 蒸发损失 空气冷凝器 单位面积节水量 水蒸气冷凝
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贵阳某数据中心多种空调形式的应用分析 被引量:2
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作者 王晨平 魏俊旗 +2 位作者 吴玲 王克勇 陈璐 《暖通空调》 2024年第2期131-136,共6页
以贵阳某数据中心为研究载体,通过对工程概况、气候条件、资源条件、空调原理和技术方案的分析,对比探究了各空调方案的机柜出架数量、节能性和经济指标。结果表明:磁悬浮蒸发相变冷却空调方案建设投资高,但能够大幅度提高机柜出架数量... 以贵阳某数据中心为研究载体,通过对工程概况、气候条件、资源条件、空调原理和技术方案的分析,对比探究了各空调方案的机柜出架数量、节能性和经济指标。结果表明:磁悬浮蒸发相变冷却空调方案建设投资高,但能够大幅度提高机柜出架数量和项目收益;该空调系统全年耗电量较少,但水资源消耗大。间接蒸发冷却空调方案的节能性最优,但是机柜出架数量最少,单位功耗造价高,利润率低。水冷式冷水空调方案节能性差,机柜出架数量较少,但建设投资低。 展开更多
关键词 数据中心 空调 水冷式冷水系统 间接蒸发冷却 磁悬浮蒸发相变 制冷负载因子(CLF) 水资源利用效率(WUE)
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空冷岛喷嘴预冷模拟研究
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作者 岳震 高社民 +1 位作者 陈国磊 李玉龙 《汽轮机技术》 北大核心 2024年第1期25-28,共4页
直接空冷岛的换热效果受气温影响严重,为提高夏季高温工况下空冷岛的冷却效果,常采用喷水减温技术。以西北地区某空冷机组为例,采用数值模拟计算分析了喷嘴喷水角度、喷水量和喷水压力对冷却效果的影响。为更好地分析喷嘴喷出的液滴在... 直接空冷岛的换热效果受气温影响严重,为提高夏季高温工况下空冷岛的冷却效果,常采用喷水减温技术。以西北地区某空冷机组为例,采用数值模拟计算分析了喷嘴喷水角度、喷水量和喷水压力对冷却效果的影响。为更好地分析喷嘴喷出的液滴在空间上的发展并量化冷却效果,采用了新的冷却效率。研究结果表明:在本文研究参数内,随着流动距离的增加,冷却效率逐渐提高。喷水量对冷却效率影响最大,喷水量分别为0.48kg/s和1.58kg/s时的冷却效率分别为24.472%和48.071%,冷却效率几乎翻倍,而喷嘴喷水压力的影响稍弱,喷嘴喷水角度影响最小。在调整喷嘴参数时可以着重考虑喷嘴喷水量和喷水压力。 展开更多
关键词 直接空冷系统 喷水预冷 数值计算 冷却效率
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气侧均流装置对冷却三角单元流动传热特性影响的实验研究
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作者 郭滔 于海洋 +5 位作者 冯海波 袁汉川 田兵 杨玉杰 赵元宾 赵倩 《发电技术》 CSCD 2024年第1期79-89,共11页
对于间接空冷系统冷端基本传热元件−冷却三角单元,通过在其加装及相邻未加装气侧均流装置冷却三角单元内的两侧冷却柱沿散热管束横向布置风速、风温、壁温测点,进一步在左右两侧出水柱布置壁温测点,对比分析两侧冷却柱沿散热管束横向迎... 对于间接空冷系统冷端基本传热元件−冷却三角单元,通过在其加装及相邻未加装气侧均流装置冷却三角单元内的两侧冷却柱沿散热管束横向布置风速、风温、壁温测点,进一步在左右两侧出水柱布置壁温测点,对比分析两侧冷却柱沿散热管束横向迎风风速、风温、壁温及出水壁温的变化规律,研究气侧均流装置对冷却三角单元流动传热特性及出水壁温分布的影响机制。研究结果表明:加装气侧均流装置后冷却三角单元两侧冷却柱沿散热管束横向迎风风温、壁温分布更加均匀,两侧出水柱壁温均值更低,且降低了两侧出水柱壁温差,气侧均流装置优化了两侧冷却柱的换热均匀性。 展开更多
关键词 煤电机组 间接空冷系统 冷却三角单元 气侧均流装置 流动传热 水温分布
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夏热冬冷地区空调冷热源配置的多目标优化
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作者 朱晓玥 杨玲 +2 位作者 熊帝战 范钟引 刘希臣 《建筑节能(中英文)》 CAS 2024年第7期87-94,共8页
为实现“双碳”背景下清零建筑直接碳排放的目标,夏热冬冷地区建筑空调冷热源越来越多地采用空气源热泵加水冷式冷水机组的复合架构。其中,空气源热泵冬季供热,夏季与水冷式机组共同供冷。由于空气源热泵供冷能效较低,提高水冷式机组容... 为实现“双碳”背景下清零建筑直接碳排放的目标,夏热冬冷地区建筑空调冷热源越来越多地采用空气源热泵加水冷式冷水机组的复合架构。其中,空气源热泵冬季供热,夏季与水冷式机组共同供冷。由于空气源热泵供冷能效较低,提高水冷式机组容量配置,尽可能使之分担更多的冷负荷,有利于降低系统供冷能耗,但系统投资也将随之上升。因此,有必要研究复合架构下空调冷热源配置的综合优化方法。利用层次分析法,计算空调冷热源系统的节能性、环保性、经济性、节材性等不同目标维度的权重,建立空调冷热源的综合优化目标函数。设计空调冷热源配置的优化流程,并以上海某办公建筑为例进行分析。结果表明,随着水冷机组容量的增加,空调冷热源系统的全年能耗降低,耗材生产能耗、折算年费上升,而碳排放呈先降后升的规律。多目标优化方法可以更好地实现各项指标之间的平衡,为相关研究及实际项目决策提供参考。 展开更多
关键词 多目标优化 层次分析法 空气源热泵 水冷式冷水机组 夏热冬冷地区
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