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Clogging caused by coupled grain migration and compaction effect during groundwater recharge for unconsolidated sandstone reservoir in groundwater-source heat pump
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作者 Fujian Yang Jing Luo +3 位作者 Guiling Wang Hejuan Liu Dawei Hu Hui Zhou 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期2947-2959,共13页
In unconsolidated sandstone reservoirs,presence of numerous movable grains and a complex grain size composition necessitates a clear understanding of the physical clogging process for effective groundwater recharge in... In unconsolidated sandstone reservoirs,presence of numerous movable grains and a complex grain size composition necessitates a clear understanding of the physical clogging process for effective groundwater recharge in groundwater-source heat pump systems.To investigate this,a series of seepage experiments was conducted under in situ stress conditions using unconsolidated sandstone samples with varying grain compositions.The clogging phenomenon arises from the combined effects of grain migration and compaction,wherein the migration of both original and secondary crushed fine-grain particles blocks the seepage channels.Notably,grain composition influences the migration and transport properties of the grains.For samples composed of smaller grains,the apparent permeability demonstrates a transition from stability to decrease.In contrast,samples with larger grains experience a skip at the stability stage and directly enter the decrease stage,with a minor exception of a slight increase observed.Furthermore,a unique failure mode characterized by diameter shrinkage in the upper part of the sample is observed due to the combined effects of grain migration and in situ stress-induced compaction.These testing results contribute to a better understanding of the clogging mechanism caused by the coupled effects of grain migration and compaction during groundwater recharge in unconsolidated sandstone reservoirs used in groundwater-source heat pump systems. 展开更多
关键词 Groundwater-source heat pump CLOGGING Grain migration Compaction effect Groundwater recharge Unconsolidated sandstone
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Developing Operational Model for Heat Pumps as Space Heating and Domestic Hot Water Provider
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作者 Rilwan Olaolu Oliyide Jose B. Hernandez 《Open Journal of Applied Sciences》 2024年第10期2880-2900,共21页
In the United Kingdom, means of meeting domestic heating is being electrified to decarbonise in effort to reduce the greenhouse gases emissions from the burning of natural gas. Therefore, the uptake of heat pumps is o... In the United Kingdom, means of meeting domestic heating is being electrified to decarbonise in effort to reduce the greenhouse gases emissions from the burning of natural gas. Therefore, the uptake of heat pumps is on the increase. The operation and working principle of heat pumps must be well understood in the investigations of their impacts on the grid and the grid assets, especially distribution transformers which could be overloaded due to higher peak load demand. This work develops an operational model of heat pumps as combined space heating and domestic hot water provider implemented in MATLAB. The developed operational model of heat pumps is adaptable and repeatable for different input parameters. The developed model is used to generate daily average demand profiles of heat pumps for a typical winter weekday and a typical summer weekday. The generated demand profiles of heat pumps by the developed model compared well with the demand profiles of heat pumps generated from actual field projects which are usually expensive and time-tasking. 展开更多
关键词 heat pumps Greenhouse Gases Space heating Domestic Hot Water TRANSFORMER MATLAB
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Investigation of energy-efficient heat pump assisted heterogeneous azeotropic distillation for separating of acetonitrile/ethyl acetate/n-hexane mixture 被引量:1
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作者 Xinhao Li Qing Ye +4 位作者 Jinlong Li Lingqiang Yan Xue Jian Licheng Xie Jianyu Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第3期20-33,共14页
The conventional distillation is hard to accomplish the separation of acetonitrile/ethyl acetate/n-hexane mixture. Herein, a heterogeneous azeotropic distillation(HAD) without adding entrainer is proposed to separate ... The conventional distillation is hard to accomplish the separation of acetonitrile/ethyl acetate/n-hexane mixture. Herein, a heterogeneous azeotropic distillation(HAD) without adding entrainer is proposed to separate ternary mixture. The proposed scheme is optimized via the simulated annealing algorithm and minimum total annual cost(TAC) is used as objective functions. To minimize energy consumption,heat pump is added on the basis of optimal heterogeneous azeotropic distillation and heat integration technology is used to further improve the energy recovery. The TAC, gas emission, energy consumption and exergy destruction are used to discuss the economy and environmental protection of processes.Among all the processes, the heat pump with higher preheating temperature(HPT) assisted HAD process by combining with heat integration(HAD-HPT-HI) has best performances on economic, environment,energy and exergy. Compared with conventional HAD process, the HAD-HPT-HI achieves the reductions of 52.17%, 68.86%, 65.87% and 65.46% on TAC, total energy consumption, gas emissions and exergy destruction, respectively. 展开更多
关键词 Heterogeneous azeotropic distillation ENERGY-SAVING SA algorithm heat pump
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A review of low-temperature heat recovery technologies for industry processes 被引量:13
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作者 Li Xia Renmin Liu +4 位作者 Yiting Zeng Peng Zhou Jingjing Liu Xiaorong Cao Shuguang Xiang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第10期2227-2237,共11页
The amount of low-temperature heat generated in industrial processes is high,but recycling is limited due to low grade and low recycling efficiency,which is one of the reasons for low energy efficiency.It implies that... The amount of low-temperature heat generated in industrial processes is high,but recycling is limited due to low grade and low recycling efficiency,which is one of the reasons for low energy efficiency.It implies that there is a great potential for low-temperature heat recovery and utilization.This article provided a detailed review of recent advances in the development of low-temperature thermal upgrades,power generation,refrigeration,and thermal energy storage.The detailed description will be given from the aspects of system structure improvement,work medium improvement,and thermodynamic and economic performance evaluation.It also pointed out the development bottlenecks and future development trends of various technologies.The low-temperature heat combined utilization technology can recover waste heat in an all-round and effective manner,and has great development prospects. 展开更多
关键词 low-temperature heat heat pump Power generation heat STORAGE REFRIGERATION
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Numerical simulation analysis on multi-layer low-temperature heating method of asphalt pavement in hot in-place recycling 被引量:4
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作者 MA Deng-cheng LAN Fen 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第12期3793-3806,共14页
Asphalt mixture pavement reheating is one of the important steps in hot in-place recycling(HIR).To improve the heating speed of asphalt pavement in HIR,based on the numerical analysis model of asphalt mixture heating ... Asphalt mixture pavement reheating is one of the important steps in hot in-place recycling(HIR).To improve the heating speed of asphalt pavement in HIR,based on the numerical analysis model of asphalt mixture heating process,a new multi-layer low-temperature heating method(MLHM)was proposed.Considering input heat flux,the thermal capacity and thermal resistance of asphalt mixture,the heat transfer model was established based on energy conservation law.By heating the asphalt mixture in layers,it changes the situation that the heat energy can only be input from the upper surface of the asphalt mixture pavement.Through the simulation of the heating method of asphalt mixture in the existing technology,the result shows that the existing heating methods lead to serious aging or charring of the asphalt mixture.By MLHM,the upper and the bottom of the asphalt mixture are heated at the same time,and the heating temperature is lower than other heat methods,which not only reduces the heating thickness and increases the heating area of the asphalt mixture pavement,but also improves the heating speed,saves the energy resource and ensures the heating quality.Especially,by MLHM,the heating uniformity is better and speed is faster. 展开更多
关键词 asphalt pavement hot in-place recycling heating speed heating uniformity MULTI-LAYER low-temperature
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Novel Radiation-Adjustable Heating Terminal Based on Flat Heat Pipe Combined with Air Source Heat Pump
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作者 Yifan Wu Hongli Sun +3 位作者 Mengfan Duan Borong Lin Hengxin Zhao Chaohung Liu 《Engineering》 SCIE EI CAS CSCD 2023年第1期192-207,共16页
The electrification of building heating is an effective way to meet the global carbon target. As a clean and sustainable electrified heating technology, air-source heat pumps (ASHPs) are widely used in areas lacking c... The electrification of building heating is an effective way to meet the global carbon target. As a clean and sustainable electrified heating technology, air-source heat pumps (ASHPs) are widely used in areas lacking central heating. However, as a major component of space heating, heating terminals might not fit well with ASHP in order to achieve both intermittency and comfort. Therefore, this study proposes a novel radiation-adjustable heating terminal combined with an ASHP to achieve electrification, intermittency, and better thermal comfort. Radiant terminals currently suffer from three major problems: limited maximum heating capacity, inability to freely adapt, and difficulty with combining them with ASHPs. These problems were solved by improving the structural design of the novel terminal (Improvement A–E). Results showed that the maximum heating capacity increased by 23.6% and radiation heat transfer ratio from 10.1% to 30.9% was provided for users with the novel terminal. Further, new flat heat pipe (FHP) design improved stability (compressor oil return), intermittency (refrigerant thermal inertia), and safety (refrigerant leakage risk) by reducing the length of exposed refrigerant pipes. Furthermore, a new phased operation strategy was proposed for the novel terminal, and the adjustability of the terminal was improved. The results can be used as reference information for decarbonizing buildings by electrifying heating terminals. 展开更多
关键词 Novel heating terminal Air-source heat pump Structural impr ovement design Maximum heating capacity Rapid adjustability Room temperature distribution
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Modeling and Optimization of Solar Collector Design for the Improvement of Solar-Air Source Heat Pump Building Heating System
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作者 Jiarui Wu Yuzhen Kang Junxiao Feng 《Energy Engineering》 EI 2023年第12期2783-2802,共20页
To enhance system stability,solar collectors have been integrated with air-source heat pumps.This integration facilitates the concurrent utilization of solar and air as energy sources for the system,leading to an impr... To enhance system stability,solar collectors have been integrated with air-source heat pumps.This integration facilitates the concurrent utilization of solar and air as energy sources for the system,leading to an improvement in the system’s heat generation coefficient,overall efficiency,and stability.In this study,we focus on a residential building located in Lhasa as the target for heating purposes.Initially,we simulate and analyze a solar-air source heat pump combined heating system.Subsequently,while ensuring the system meets user requirements,we examine the influence of solar collector installation angles and collector area on the performance of the solar-air source heat pump dual heating system.Through this analysis,we determine the optimal installation angle and collector area to optimize system performance. 展开更多
关键词 Solar energy air source heat pump optimization model solar-air heat pump heating system
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Research on Operation Optimization of Heating System Based on Electric Storage Coupled Solar Energy and Air Source Heat Pump
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作者 Jingxiao Han Chuanzhao Zhang +5 位作者 LuWang ZengjunChang Qing Zhao Ying Shi JiaruiWu Xiangfei Kong 《Energy Engineering》 EI 2023年第9期1991-2011,共21页
For heating systems based on electricity storage coupled with solar energy and an air source heat pump(ECSA),choosing the appropriate combination of heat sources according to local conditions is the key to improving e... For heating systems based on electricity storage coupled with solar energy and an air source heat pump(ECSA),choosing the appropriate combination of heat sources according to local conditions is the key to improving economic efficiency.In this paper,four cities in three climatic regions in China were selected,namely Nanjing in the hot summer and cold winter region,Tianjin in the cold region,Shenyang and Harbin in the severe cold winter region.The levelized cost of heat(LCOH)was used as the economic evaluation index,and the energy consumption and emissions of different pollutants were analyzed.TRNSYS software was used to simulate and analyze the system performance.The Hooke-Jeeves optimization algorithm and GenOpt software were used to optimize the system parameters.The results showed that ECSA systemhad an excellent operation effect in cold region and hot summer and cold winter region.Compared with ECS system,the systemenergy consumption,and the emission of different pollutants of ECSA system can be reduced by a maximum of 1.37 times.In cold region,the initial investment in an air source heat pump is higher due to the lower ambient temperature,resulting in an increase in the LOCH value of ECSA system.After the LOCH value of ECSA system in each region was optimized,the heating cost of the system was reduced,but also resulted in an increase in energy consumption and the emission of different pollutant gases. 展开更多
关键词 Electric heat storage solar energy air source heat pump multi-objective optimization method LOCH
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Synthesis and Design of Distillation Columns for Wide-Boiling Binary Mixtures with Vapor Recompression Heat Pumps
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作者 Shi Li 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2023年第4期127-138,共12页
The vapor recompression heat pump(VRHP) distillation technology offers significant improvements in energy efficiency for distillation systems with small temperature differences between the top and bottom of the column... The vapor recompression heat pump(VRHP) distillation technology offers significant improvements in energy efficiency for distillation systems with small temperature differences between the top and bottom of the column. However, the separation of wide-boiling binary mixtures leads to substantial temperature differences between the top and bottom of the column. This limits the applicability of conventional VRHP due to high capital costs and strict performance requirements of the compressor. To overcome these challenges and to accommodate compressor operating conditions, a novel synthesis and design method is introduced to integrate VRHPs with wide-boiling binary mixture distillation columns(WBMDCs). This method enables quick determination of an initial configuration for the integrated WBMDC-VRHP system and helps identify the optimum configuration with the minimum total annual cost. Two examples, namely the separation of benzene/toluene and isopropanol/chlorobenzene, are employed to derive optimum configurations of the WBMDC-VRHP and compare them with the WBMDC. A systematic comparison between the WBMDC-VRHP and WBMDC demonstrates the superior steady-state performance and economic efficiency of the WBMDC-VRHP. 展开更多
关键词 vapor recompression heat pump wide-boiling binary mixtures distillation column energy saving synthesis and design
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Low-temperature heat capacities and standard molar enthalpy of formation of pyridine-2,6-dicarboxylic acid 被引量:2
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作者 杨伟伟 邸友莹 +1 位作者 孔玉霞 谭志诚 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第6期188-194,共7页
This paper reports that the low-temperature heat capacities of pyridine-2,6-dicarboxylic acid were measured by a precision automatic calorimeter over a temperature range from 78 K to 380 K. A polynomial equation of he... This paper reports that the low-temperature heat capacities of pyridine-2,6-dicarboxylic acid were measured by a precision automatic calorimeter over a temperature range from 78 K to 380 K. A polynomial equation of heat capacities as a function of temperature was fitted by the least-squares method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at intervals of 5 K. The constant-volume energy of combustion of the compound was determined by means of a precision rotating-bomb combustion calorimeter. The standard molar enthalpy of combustion of the compound was derived from the constant-volume energy of combustion. The standard molar enthalpy of formation of the compound was calculated from a combination of the datum of the standard molar enthalpy of combustion of the compound with other auxiliary thermodynamic quantities through a Hess thermochemical cycle. 展开更多
关键词 pyridine-2 6-dicarboxylic acid adiabatic calorimetry low-temperature heat capacity standard molar enthalpy of formation
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Exergo-Environmental Study of a Recent Organic Solar Hybrid Heat Pump
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作者 Rabeb Toujani Nahla Bouaziz 《Fluid Dynamics & Materials Processing》 EI 2023年第4期991-1001,共11页
A hybrid heat pump(compression/absorption)with an integrated thermal photovoltaic unit is studied.The considered working fluids are organic mixtures:R245fa/DMAC and R236fa/DMAC,chosen for their low Global Warming Pote... A hybrid heat pump(compression/absorption)with an integrated thermal photovoltaic unit is studied.The considered working fluids are organic mixtures:R245fa/DMAC and R236fa/DMAC,chosen for their low Global Warming Potential.The main objective is the optimization of energy efficiency in order to minimize the environmental impact through the implementation of a sustainable strategy.It is shown that Exergy Analysis itself is a valuable tool in energy integration.Within the imposed framework of minimizing total annual costs,entropy analysis can be instrumental in determining the optimal plant concept,optimizing energy conversion and use,and improving profitability.The present results are discussed under the optimistic hope that they may help to define new energy and environmental policies. 展开更多
关键词 Impact environmental exergy analysis CO_(2)emissions solar hybrid heat pump
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Thermo-Economic Performance of Geothermal Driven High-Temperature Flash Tank Vapor Injection Heat Pump System:A Comparison Study
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作者 Huashan Li Xiaoshuang Zhao +2 位作者 Sihao Huang Lingbao Wang Jiongcong Chen 《Energy Engineering》 EI 2023年第8期1817-1835,共19页
Process heating constitutes a significant share of final energy consumption in the industrial sector around the world.In this paper,a high-temperature heat pump(HTHP)using flash tank vapor injection technology(FTVI)is... Process heating constitutes a significant share of final energy consumption in the industrial sector around the world.In this paper,a high-temperature heat pump(HTHP)using flash tank vapor injection technology(FTVI)is proposed to develop low-temperature geothermal source for industrial process heating with temperature above 100°C.With heat sink output temperatures between 120°C and 150°C,the thermo-economic performance of the FTVI HTHP system using R1234ze(Z)as refrigerant is analyzed and also compared to the single-stage vapor compression(SSVC)system by employing the developed mathematical model.The coefficient of performance(COP),exergy efficiency(ηexe),net present value(NPV)and payback period(PBP)are used as performance indicators.The results show that under the typical working conditions,the COP andηexe of FTVI HTHP system are 3.00 and 59.66%,respectively,and the corresponding NPV and PBP reach 8.13×106 CNY and 4.13 years,respectively.Under the high-temperature heating conditions,the thermo-economic performance of the FTVI HTHP system is significantly better than that of the SSVC system,and the larger the temperature lift,the greater the thermo-economic advantage of the FTVI HTHP system.Additionally,the FTVI HTHP system is more capable than the SSVC system in absorbing the financial risks associated with changes of electricity price and natural gas price. 展开更多
关键词 Geothermal water high-temperature heat pump flash tank vapor injection thermo-economic performance
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Impact of the Heat Pump on the Environment
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作者 Jovan Mitrović 《Journal of Power and Energy Engineering》 2023年第6期26-33,共8页
The paper deals with the impact of a mechanical compression heat pump, operated by electrical energy, on the environment. Irrespective of its origin and the history of its production, this energy pollutes the environm... The paper deals with the impact of a mechanical compression heat pump, operated by electrical energy, on the environment. Irrespective of its origin and the history of its production, this energy pollutes the environment as waste heat. The operational energy, obtained from the so-called alternative energy sources (wind, water energy), also burdens the environment as waste heat. This is not the case with the solar energy. A direct conversion of the Sun’s rays into electricity does not additionally affect the environment, compared to their direct conversion into heat without our intervention. 展开更多
关键词 heat pump ENVIRONMENT
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Simulation Study of the Control Strategy of a DC Inverter Heat Pump Using a DC Distribution Network
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作者 Siwei Han Xianglong Li +3 位作者 Wei Zhao Linyu Wang Anqi Liang Shuang Zeng 《Energy Engineering》 EI 2023年第6期1421-1444,共24页
Photovoltaics,energy storage,direct current and flexibility(PEDF)are important pillars of achievement on the path to manufacturing nearly zero energy buildings(NZEBs).HVAC systems,which are an important part of public... Photovoltaics,energy storage,direct current and flexibility(PEDF)are important pillars of achievement on the path to manufacturing nearly zero energy buildings(NZEBs).HVAC systems,which are an important part of public buildings,play a key role in adapting to PDEF systems.This research studied the basic principles and operational control strategies of a DC inverter heat pump using a DC distribution network with the aim of contributing to the development and application of small DC distribution systems.Along with the characteristics of a DC distribution network and different operating conditions,a DC inverter heat pump has the ability to adapt to changes in the DC bus voltage and adds flexibility to the system.Theoretical models of the DC inverter heat pump integrated with an ice storage unit were developed.The control strategies of the DC inverter heat pump system considered the influence of both room temperature and varied bus voltage.A simulation study was conducted using MATLAB&Simulink software with simulation results validated by experimental data.The results showed that:(1)The bus fluctuation under the rated working voltage had little effect on the operation of the unit;(2)When the bus voltage was fluctuating from 80%-90%or 105%-107%,the heat pump could still operate normally by reducing the frequency;(3)When the bus voltage was less than 80%or more than 107%,the unit needed to be shut down for the sake of equipment safety,so that the energy storage device could adjust to the sharp decrease or rise of voltage. 展开更多
关键词 Photovoltaics energy storage direct current and flexibility DC inverter heat pump MATLAB&Simulink control strategy
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Performance analysis of deep borehole heat exchangers for decarbonization of heating systems
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作者 Andreas E.D.Lund 《Deep Underground Science and Engineering》 2024年第3期349-357,共9页
Meeting the climate change mitigation targets will require a substantial shift from fossil to clean fuels in the heating sector.Heat pumps with deep borehole exchangers are a promising solution to reduce emissions.Her... Meeting the climate change mitigation targets will require a substantial shift from fossil to clean fuels in the heating sector.Heat pumps with deep borehole exchangers are a promising solution to reduce emissions.Here the thermal behavior of deep borehole exchangers(DBHEs)ranging from 1 to 2 km was analyzed for various heat flow profiles.A strong correlation between thermal energy extraction and power output from DBHEs was found,also influenced by the heating profile employed.Longer operating time over the year typically resulted in higher energy production,while shorter one yielded higher average thermal power output,highlighting the importance of the choice of heating strategy and system design for optimal performance of DBHEs.Short breaks in operation for regenerating the borehole,for example,with waste heat,proved to be favorable for the performance yielding an overall heat output close to the same as with continuous extraction of heat.The results demonstrate the usefulness of deep boreholes for dense urban areas with less available space.As the heat production from a single DBHE in Finnish conditions ranges from half up to even a few GWh a year,the technology is best suitable for larger heat loads. 展开更多
关键词 clean energy deep borehole exchangers energy transition geothermal heat ground-coupled heat pump
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Assessment of Low Global Warming Potential Refrigerants for Waste Heat Recovery in Data Center with On-Chip Two-Phase Cooling Loop
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作者 Yuming Zhao Jing Wang +3 位作者 Bin Sun Zhenshang Wang Huashan Li Jiongcong Chen 《Frontiers in Heat and Mass Transfer》 EI 2024年第4期1171-1188,共18页
Data centers(DCs)are highly energy-intensive facilities,where about 30%–50%of the power consumed is attributable to the cooling of information technology equipment.This makes liquid cooling,especially in twophase mod... Data centers(DCs)are highly energy-intensive facilities,where about 30%–50%of the power consumed is attributable to the cooling of information technology equipment.This makes liquid cooling,especially in twophase mode,as an alternative to air cooling for the microprocessors in servers of interest.The need to meet the increased power density of server racks in high-performance DCs,along with the push towards lower global warming potential(GWP)refrigerants due to environmental concerns,has motivated research on the selection of two-phase heat transfer fluids for cooling servers while simultaneously recovering waste heat.With this regard,a heat pump-assisted absorption chiller(HPAAC)system for recovering waste heat in DCs with an on-chip twophase cooling loop driven by the compressor is proposed in the present paper and the low GWP hydrofluoroolefin refrigerants,including R1224yd(Z),R1233zd(E),R1234yf,R1234ze(E),R1234ze(Z),R1243zf and R1336mzz(Z),are evaluated and compared against R245fa as server coolant.For theHPAAC system,beginning with the development of energy and economic models,the performance is analyzed through both a parametric study and optimization using the coefficient of performance(COP),energy saving ratio(ESR),payback period(PBP)and net present value(NPV)as thermo-economic indicators.Using a standard vapor compression cooling system as a benchmark,the results indicate that with the evaporation temperature between 50℃and 70℃and the subcooling degree ranging from5℃to 15°C,R1233zd(E)with moderate compressor suction pressure and pressure ratio is the best refrigerant for the HPAAC systemwhile R1234yf performs the worst.More importantly,R1233zd(E)is also superior to R245fa based on thermo-economic performance,especially under work conditions with relatively lower evaporation temperature as well as subcooling degree.Under the given working conditions,the overall COP,ESR,NPV,and PBP of R1233zd(E)HPAAC with optimum subcooling degree range from4.99 to 11.27,25.53 to 64.59,1.13 to 4.10×10^(7) CNY and 5.77 to 2.22 years,respectively.Besides,the thermo-economic performance of R1233zd(E)HPAAC under optimum working conditions in terms of subcooling degree varying with the evaporation temperature is also investigated. 展开更多
关键词 heat pump absorption chiller waste heat recovery two-phase cooling loop
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Utilization and recycling of low-temperature waste heat of stainless steel continuous annealing furnace
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作者 ZHUANG Weiqi Stainless Steel Business Unit,Baoshan Iron & Steel Co.,Ltd.,Shanghai 200431,China 《Baosteel Technical Research》 CAS 2010年第S1期134-,共1页
Stainless steel continuous annealing furnace is mainly used for heat treatment of hot-rolled strip steel.The combustion air will be enabled to heat to 520℃by waste heat recovery system,but the discharge temperature i... Stainless steel continuous annealing furnace is mainly used for heat treatment of hot-rolled strip steel.The combustion air will be enabled to heat to 520℃by waste heat recovery system,but the discharge temperature is still up to about 300℃.Owing to with development of global emphasis on energy conservation energy saving and discharge reduction,it's significant to lower the discharge temperature to below 200℃, for the sake of achieving rational use of waste heat resource.Through the analysis of the existing heat recovery system by this study,it is proved that mixing low temperature with flue gas in high temperature standard will increase the capacity of the flue gas and deteriorate the quality of remaining heat resource.In stead of that,increasing the combustion air temperature to 600℃on the basis of stability temperature for the prerequisite of recuperator design,and giving priority to reducing fuel consumption are the better way.The recovery and recycle of low temperature gas are also be introduced.It is demonstrated by the way of setting a secondary recuperator at the exit of the primary recuperator,and using low temperature flue gas to heat the air used for drying the strip steel,the exhuast temperature of flue gas can be reduced to lower than 200℃.At the same time,the steam required for heating air is saved,the energy reserve as high as 2 300 t of standard coal per year. 展开更多
关键词 low-temperature waste gas heat RECYCLING energy saving
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Low-temperature heat capacities and standard molar enthalpy of formation of 4-(2-aminoethyl)-phenol (C_8H_(11)NO)
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作者 邸友莹 孔玉霞 +1 位作者 杨伟伟 谭志诚 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第9期3276-3283,共8页
This paper reports that low-temperature heat capacities of 4-(2-aminoethyl)-phenol (C8H11NO) are measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial eq... This paper reports that low-temperature heat capacities of 4-(2-aminoethyl)-phenol (C8H11NO) are measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of heat capacities as a function of the temperature was fitted by the least square method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15K were calculated and tabulated at the interval of 5K. The energy equivalent, εcalor, of the oxygen-bomb combustion calorimeter has been determined from 0.68g of NIST 39i benzoic acid to be εcalor=(14674.69±17.49)J·K^-1. The constant-volume energy of combustion of the compound at T=298.15 K was measured by a precision oxygen-bomb combustion calorimeter to be ΔcU=-(32374.25±12.93)J·g^-1. The standard molar enthalpy of combustion for the compound was calculated to be ΔcHm = -(4445.47 ± 1.77) kJ·mol^-1 according to the definition of enthalpy of combustion and other thermodynamic principles. Finally, the standard molar enthalpy of formation of the compound was derived to be ΔfHm(C8H11NO, s)=-(274.68 ±2.06) kJ·mol^-1, in accordance with Hess law. 展开更多
关键词 4-(2-aminoethyl)-phenol adiabatic calorimetry low-temperature heat capacity standard molar enthalpy of formation
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Low-temperature heat capacities of crystalline Ho(Gly)_(3)Cl_(3)·3H_(2)O from 78 to 348 K
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作者 张景楠 王辉 +3 位作者 谭志诚 刘北平 史全 童波 《Journal of Rare Earths》 SCIE EI CAS CSCD 2009年第6期919-922,共4页
Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temper... Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temperature range,the heat capacities increased in a smooth and continuous manner and no phase transition or thermal anomaly occurred.Therefore,the sample was stable in the above temperature range.The values of experimental heat capacities were fitted to a polynomial equation with least square method and ... 展开更多
关键词 rare-earth complex Ho(Gly)3Cl3·3H2O low-temperature heat capacities thermodynamic functions
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Piezoelectric Power Harvesting Process via Phase Changes of Low-Boiling-Point Medium Together with Water for Recovering Low-Temperature Heats
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作者 Seiichi Deguchi Akinori Miyajima +8 位作者 Hajime Arimura Haruna Banno Noriyuki Kobayashi Norifumi Isu Kentaro Takagi Tsuyoshi Inoue Takashi Nozoe Seigo Saito Takahiko Sano 《Journal of Power and Energy Engineering》 2018年第11期65-77,共13页
Low-temperature thermal energy conversions down to exergy zero to electric power must contribute energy sustainability. That is to say, reinforcements of power harvesting technologies from extremely low temperatures l... Low-temperature thermal energy conversions down to exergy zero to electric power must contribute energy sustainability. That is to say, reinforcements of power harvesting technologies from extremely low temperatures less than 373 K might be at least one of minimum roles for the current generations. Then, piezoelectric power harvesting process for recovering low-temperature heats was invented by using a unique biphasic operating medium of an underlying water-insoluble/low-boiling-point medium (i.e. NOVEC manufactured by 3M Japan Ltd.) in small quantity and upper-layered water in large quantity. The higher piezoelectric power harvesting densities were naturally revealed with an increase in heating temperatures. Excessive cooling of the operating medium deteriorated the power harvesting efficiency. The denser operating medium was surpassingly helpful to the higher piezoelectric power harvesting density. Concretely, only about 5% density increase of main operating medium (i.e. water with dissolving alum at 0.10 mol/dm3) came to the champion piezoelectric power harvesting density of 92.6 pW/dm2 in this study, which was about 1.4 times compared to that with the original biphasic medium of pure water together with a small quantity of NOVEC. 展开更多
关键词 PIEZOELECTRIC POWER Generation low-temperature heat Recovery BIPHASIC MEDIUM Phase Change Multiphase Flow POWER Harvesting
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