The evaporative cooling,which assists the refrigeration machinery air-conditioning systems test-rig,has been designed.Its structure and working principle were described,and the performance test was conducted and analy...The evaporative cooling,which assists the refrigeration machinery air-conditioning systems test-rig,has been designed.Its structure and working principle were described,and the performance test was conducted and analyzed.The test shows that making full use of the evaporative cooling "free cooling" in Spring and Autumn seasons can fully meet the requirements of air-conditioned comfort through the switch of the function in different seasons.Taking into account the evaporative cooling fan and pump energy consumption,compared with the traditional mechanical refrigeration system,more than 80 percent of energy can be saved,and the energy efficiency ratio of the Unit(EER)is as high as 7.63.Using the two stages of indirect evaporative cooling to pre-cool the new wind in summer,under the conditions of the same air supply temperature requirements,0.83 kg/s chilled water saved can be equivalent to the traditional mechanical refrigeration system,and when the new wind ratio up to 50 percent,more than 10 percent load was reduced in mechanical refrigeration system.The overall EER increased about 35 percent.展开更多
Heat emission and the voltage are the main factors affecting the refrigerating capacity of semiconductor refrigerator.Some experiments were designed to obtain their influence on refrigerating capacity of semiconductor...Heat emission and the voltage are the main factors affecting the refrigerating capacity of semiconductor refrigerator.Some experiments were designed to obtain their influence on refrigerating capacity of semiconductor and the interaction between heat emission and the voltage.The results show that fixing the heat dissipation,there is an optimal working voltage for the semiconductor module;and if improving the heat emission,the refrigerating capacity increases and the optimal voltage becomes larger.This can provide the basis for the optimal design of semiconductor refrigeration.展开更多
This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of resource loss and an ...This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of resource loss and an emission entropy from the condense heat recovery system in the air conditioning refrigerating machine were introduced.For the evaluation of the entropies,we developed a new algorithm for the parameter identification,called the composite influence coefficient,based on the Least Squares Support Vector Machine method.By simulation,the numerical experiments shows that the Least Squares Support Vector Machine method is one of the powerful methods for the parameter identification to compute the damage entropy of the condense heat,with the largest training error being-0.025(the relative error being-3.56%),and the biggest test error being 0.015(the relative error being 2.5%).展开更多
In the travel process of urban residents,travelers will take a series of activities such as imitation and exclusion by observing other people’s travel modes,which affects their following trips.This process can be see...In the travel process of urban residents,travelers will take a series of activities such as imitation and exclusion by observing other people’s travel modes,which affects their following trips.This process can be seen as a repeated game between members of the travelers.Based on the analysis of this game and its evolution trend,a multi-dimensional game model of low-carbon travel for residents is established.The two dimensional game strategies include whether to accept the low-carbon concept and whether to choose low-carbon travel.Combined with evolutionary game theory,the low-carbon travel choices of residents in different cities are simulated,and the evolutionary stability strategies are obtained.Finally,the influences of the main parameters of the model on the evolution process and stability strategies are discussed.The results show that travelers would develop towards two trends.Cities with more developed public traffic system have a higher proportion of receiving low-carbon concept and choosing low-carbon travel.Cities with underdeveloped public transport system could increase this proportion by some measures such as encouraging residents to choose slow transport and increasing the propaganda of low-carbon travel,but the positive effects of the measures like propaganda have a limited impact on the proportion.展开更多
In order to investigate the regularity of metal magnetic signals of ferromagnetic materials under the effect of applied load, the static tensile test of Q235 steel and 18CrNiWA steel plate specimens were conducted and...In order to investigate the regularity of metal magnetic signals of ferromagnetic materials under the effect of applied load, the static tensile test of Q235 steel and 18CrNiWA steel plate specimens were conducted and metal magnetic memory signals of specimens were measured during the test process. The influencing factors of metal magnetic memory signals and the relationship between axial applied load and signals were analyzed. The fracture and microstructure of the specimens were observed. The results show that the magnetic signals corresponding to the measured points change linearly approximately with increasing axial load. The microstructure of Q235 steel is ferrite and perlite, whereas that of 18CrNiWA steel is bainite and low-carbon martensite. The fracture of these two kinds of specimens is ductile rupture; carbon content of specimen materials and dislocation glide give much contribution to the characteristics of magnetic curves.展开更多
Common insulation gas cannot normally work in refrigeration temperature range(153-243 K), especially in extremely cold regions. To solve this problem, this essay uses cubic equation combined with two-parameter model i...Common insulation gas cannot normally work in refrigeration temperature range(153-243 K), especially in extremely cold regions. To solve this problem, this essay uses cubic equation combined with two-parameter model in theorem of corresponding states to estimate dew-point of hybrid gas. The influence of temperature on mixing ratio is studied by using van der Waals equation. The result shows that the mixing ratio is stable during temperature-fall period. Insulation property of CF_4 and CF_4/N_2 in refrigeration temperature range is studied through self-designed low-temperature test system. The result shows when the density of hybrid gas is invariable, temperature changing has less influence on breakdown voltage, and when the mixing ratio is 20%, CF_4/N_2 is the greatest potential hybrid gas.展开更多
A model of quantum thermoacoustic refrigeration micro-cycle(QTARMC)is established in which heat leakage is considered.A single particle contained in a one-dimensional harmonic potential well is studied,and the system ...A model of quantum thermoacoustic refrigeration micro-cycle(QTARMC)is established in which heat leakage is considered.A single particle contained in a one-dimensional harmonic potential well is studied,and the system consists of countless replicas.Each particle is confined in its own potential well,whose occupation probabilities can be expressed by the thermal equilibrium Gibbs distributions.Based on the Schrodinger equation,the expressions of coefficient of performance(COP)and cooling rate for the refrigerator are obtained.Effects of heat leakage on the optimal performance are discussed.The optimal performance region of the refrigeration cycle is obtained by the using ofΩobjective function.The results obtained can enrich the thermoacoustic theory and expand the application of quantum thermodynamics.展开更多
Some magnetocaloric materials were used successfully in magnetic refrigeration application and became one of the critical parts of magnetic refrigeration technology whose delightful progresses were made worldwide in t...Some magnetocaloric materials were used successfully in magnetic refrigeration application and became one of the critical parts of magnetic refrigeration technology whose delightful progresses were made worldwide in the past 30 years. At the same time, the research on giant magnetocaloric materials will accelerate the development of room temperature magnetic refrigeration. In this paper, the new theoretical and experimental investigations on magnetic materials in room temperature application were described, including Gd and its binary and ternary intermetallic compounds, Mn-based compounds, La(Fe13-xMx)-based compounds and manganites. Based on the analysis of hysteresis, corrosion, cost and heat process, the comparison between different families of magnetic materials was discussed. Further research of room temperature magnetic refrigerant was suggested.展开更多
Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of...Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of similar WWTP. When the proposed measures,such as using 0.1% (volume fraction of wastewater) landfill leachate,shortening HRT by 2/3 in the primary sedimentation tank and controlling DO at 0.5 mg/L in the 3rd section of aerobic zone,are applied,15% of the carbon source can be complemented,the favorable property of activated sludge is achieved,and the nitrogen removal effect is significantly improved. The effluent NH3-N is 2 mg/L and the removal rate is 90%. The effluent TN is 17 mg/L and the removal rate is 54%. The up-to-standard discharge of the effluent is achieved. And after the optimization,the unit electricity consumption also reaches 0.21 kW/h and saves 20%.展开更多
Based on the trace of origin and development process of low-carbon economy, the paper defined the concept of low- carbon agriculture. As a case, the development of low-carbon advantage and disadvantage of agriculture ...Based on the trace of origin and development process of low-carbon economy, the paper defined the concept of low- carbon agriculture. As a case, the development of low-carbon advantage and disadvantage of agriculture in Heilongjiang Province made a systematic analysis of factors; it based on the empirical and comparative analysis of low-carbon development in Heilongjiang Province and put forward countermeasures and suggestions of agriculture. At last, the low-carbon agriculture was prospected in the future.展开更多
Grey cast iron’s welding itself is a complex proble m.So proper welding materials must be selected,complex welding techniques such as preheating before weldingslow cooling after welding etc,should be taken. However t...Grey cast iron’s welding itself is a complex proble m.So proper welding materials must be selected,complex welding techniques such as preheating before weldingslow cooling after welding etc,should be taken. However the carbon component in low-carbon steel is comparatively low,the carbo n of welded joint will diffuse to the low-carbon steel when it is welded with gr ey cast iron,which will cause the component of carbon greatly increased at the low-carbon steel side in HAZ,high carbon martensite and cracks will occur.If p reheating before weldingslow cooling after welding and other welding procedure are taken,the grey cast iron side can probably be qualified.But the carbon wi ll diffuse to HAZ of the low-carbon steel side more easily.Therefore after stud ying the weldabilities of grey cast iron and low-carbon steel,the author develo ped a new type of cast iron electrode considering the demands of factories’prac tices,and the welding technology test of grey cast iron and low-carbon steel ar e carried out. In this paper,a new type of grey cast iron electrode is developed based on the practices in factories,its ingredients and properties are introduced.The w elding tests of grey cast iron and low-carbon steel are practiced.The joint str ucture of the dissimilar metal and the appearance of weld are observed.The hard ness distribution of the welded joint is tested.The results show that the elect rode can meet the welding requirements of the grey cast iron and low-carbon stee l.There are no cracksgas pores and other defects of metallurgy in welded join t,the appearance of welded joint are good.展开更多
The mechanism of gas discharge in refrigeration temperature range is still not clear. N2, CF4, 20% CF4＋N2 and 50%CF4＋50%N2 binary gas mixtures were tested under the conditions of –153–25 ℃ and 50–2000 Pa. The ex...The mechanism of gas discharge in refrigeration temperature range is still not clear. N2, CF4, 20% CF4＋N2 and 50%CF4＋50%N2 binary gas mixtures were tested under the conditions of –153–25 ℃ and 50–2000 Pa. The experimental results show that the minimum of Paschen curves of all test samples shifts to low pressure, from 500 Pa to 200 Pa. The value of Paschen curve minimum of N2 shows remarkable fluctuation. This fluctuation is explained by molecule agglomeration and electronic mean energy. The fluctuation decreases with the increasing mixing ratio of CF4. What’s more, the value of Paschen curve minimum of CF4 decreases with temperature. This phenomenon is ascribed to attach-radiation and secondary process.展开更多
基金Xi'an Polytechnic University Graduate Innovational Foundation(chx080608)
文摘The evaporative cooling,which assists the refrigeration machinery air-conditioning systems test-rig,has been designed.Its structure and working principle were described,and the performance test was conducted and analyzed.The test shows that making full use of the evaporative cooling "free cooling" in Spring and Autumn seasons can fully meet the requirements of air-conditioned comfort through the switch of the function in different seasons.Taking into account the evaporative cooling fan and pump energy consumption,compared with the traditional mechanical refrigeration system,more than 80 percent of energy can be saved,and the energy efficiency ratio of the Unit(EER)is as high as 7.63.Using the two stages of indirect evaporative cooling to pre-cool the new wind in summer,under the conditions of the same air supply temperature requirements,0.83 kg/s chilled water saved can be equivalent to the traditional mechanical refrigeration system,and when the new wind ratio up to 50 percent,more than 10 percent load was reduced in mechanical refrigeration system.The overall EER increased about 35 percent.
基金Supported by National High Technology Research and Development Program(2006AA05Z229)National Natural Science Foundation of China(50578059)
文摘Heat emission and the voltage are the main factors affecting the refrigerating capacity of semiconductor refrigerator.Some experiments were designed to obtain their influence on refrigerating capacity of semiconductor and the interaction between heat emission and the voltage.The results show that fixing the heat dissipation,there is an optimal working voltage for the semiconductor module;and if improving the heat emission,the refrigerating capacity increases and the optimal voltage becomes larger.This can provide the basis for the optimal design of semiconductor refrigeration.
基金Supported by Program of Science and Technology of Hunan Province(2007FJ2006)Project the Program of Science and Tech-nology of Hunan Province(2007TP4030)Hunan Provincial Natural Science Foundation of China(08JJ3093)
文摘This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of resource loss and an emission entropy from the condense heat recovery system in the air conditioning refrigerating machine were introduced.For the evaluation of the entropies,we developed a new algorithm for the parameter identification,called the composite influence coefficient,based on the Least Squares Support Vector Machine method.By simulation,the numerical experiments shows that the Least Squares Support Vector Machine method is one of the powerful methods for the parameter identification to compute the damage entropy of the condense heat,with the largest training error being-0.025(the relative error being-3.56%),and the biggest test error being 0.015(the relative error being 2.5%).
基金Project(BK20160512)supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(16YJCZH027)supported by the Humanity and Social Science Youth Foundation of Ministry of Education of ChinaProject(15GLC004)supported by the Social Science Foundation of Jiangsu Province,China
文摘In the travel process of urban residents,travelers will take a series of activities such as imitation and exclusion by observing other people’s travel modes,which affects their following trips.This process can be seen as a repeated game between members of the travelers.Based on the analysis of this game and its evolution trend,a multi-dimensional game model of low-carbon travel for residents is established.The two dimensional game strategies include whether to accept the low-carbon concept and whether to choose low-carbon travel.Combined with evolutionary game theory,the low-carbon travel choices of residents in different cities are simulated,and the evolutionary stability strategies are obtained.Finally,the influences of the main parameters of the model on the evolution process and stability strategies are discussed.The results show that travelers would develop towards two trends.Cities with more developed public traffic system have a higher proportion of receiving low-carbon concept and choosing low-carbon travel.Cities with underdeveloped public transport system could increase this proportion by some measures such as encouraging residents to choose slow transport and increasing the propaganda of low-carbon travel,but the positive effects of the measures like propaganda have a limited impact on the proportion.
基金Projects(50235030, 50505052) supported by the National Natural Science Foundation of China
文摘In order to investigate the regularity of metal magnetic signals of ferromagnetic materials under the effect of applied load, the static tensile test of Q235 steel and 18CrNiWA steel plate specimens were conducted and metal magnetic memory signals of specimens were measured during the test process. The influencing factors of metal magnetic memory signals and the relationship between axial applied load and signals were analyzed. The fracture and microstructure of the specimens were observed. The results show that the magnetic signals corresponding to the measured points change linearly approximately with increasing axial load. The microstructure of Q235 steel is ferrite and perlite, whereas that of 18CrNiWA steel is bainite and low-carbon martensite. The fracture of these two kinds of specimens is ductile rupture; carbon content of specimen materials and dislocation glide give much contribution to the characteristics of magnetic curves.
基金Project(51277063)supported by the National Natural Science Foundation of China
文摘Common insulation gas cannot normally work in refrigeration temperature range(153-243 K), especially in extremely cold regions. To solve this problem, this essay uses cubic equation combined with two-parameter model in theorem of corresponding states to estimate dew-point of hybrid gas. The influence of temperature on mixing ratio is studied by using van der Waals equation. The result shows that the mixing ratio is stable during temperature-fall period. Insulation property of CF_4 and CF_4/N_2 in refrigeration temperature range is studied through self-designed low-temperature test system. The result shows when the density of hybrid gas is invariable, temperature changing has less influence on breakdown voltage, and when the mixing ratio is 20%, CF_4/N_2 is the greatest potential hybrid gas.
基金Project(51176143)supported by the National Natural Science Foundation of ChinaProject(K201919)supported by the Scientific Research Foundation of Wuhan Institute of TechnologyChina。
文摘A model of quantum thermoacoustic refrigeration micro-cycle(QTARMC)is established in which heat leakage is considered.A single particle contained in a one-dimensional harmonic potential well is studied,and the system consists of countless replicas.Each particle is confined in its own potential well,whose occupation probabilities can be expressed by the thermal equilibrium Gibbs distributions.Based on the Schrodinger equation,the expressions of coefficient of performance(COP)and cooling rate for the refrigerator are obtained.Effects of heat leakage on the optimal performance are discussed.The optimal performance region of the refrigeration cycle is obtained by the using ofΩobjective function.The results obtained can enrich the thermoacoustic theory and expand the application of quantum thermodynamics.
基金Project(50876082) supported by the National Natural Science Foundation of ChinaProject(IRT0746) supported by the Changjiang Scholars and Innovative Research Team in University
文摘Some magnetocaloric materials were used successfully in magnetic refrigeration application and became one of the critical parts of magnetic refrigeration technology whose delightful progresses were made worldwide in the past 30 years. At the same time, the research on giant magnetocaloric materials will accelerate the development of room temperature magnetic refrigeration. In this paper, the new theoretical and experimental investigations on magnetic materials in room temperature application were described, including Gd and its binary and ternary intermetallic compounds, Mn-based compounds, La(Fe13-xMx)-based compounds and manganites. Based on the analysis of hysteresis, corrosion, cost and heat process, the comparison between different families of magnetic materials was discussed. Further research of room temperature magnetic refrigerant was suggested.
基金Project (2009ZX07315-002-01) supported by Water Pollution Control and Management of Major Special Science and Technology
文摘Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of similar WWTP. When the proposed measures,such as using 0.1% (volume fraction of wastewater) landfill leachate,shortening HRT by 2/3 in the primary sedimentation tank and controlling DO at 0.5 mg/L in the 3rd section of aerobic zone,are applied,15% of the carbon source can be complemented,the favorable property of activated sludge is achieved,and the nitrogen removal effect is significantly improved. The effluent NH3-N is 2 mg/L and the removal rate is 90%. The effluent TN is 17 mg/L and the removal rate is 54%. The up-to-standard discharge of the effluent is achieved. And after the optimization,the unit electricity consumption also reaches 0.21 kW/h and saves 20%.
基金Supported by National Natural Science Foundation (71173035)Scientific and Technological Projects in Heilongjiang Province (GC10D206)Humanities and Social Science Project in Heilongjiang Province Department of Education (12514049)
文摘Based on the trace of origin and development process of low-carbon economy, the paper defined the concept of low- carbon agriculture. As a case, the development of low-carbon advantage and disadvantage of agriculture in Heilongjiang Province made a systematic analysis of factors; it based on the empirical and comparative analysis of low-carbon development in Heilongjiang Province and put forward countermeasures and suggestions of agriculture. At last, the low-carbon agriculture was prospected in the future.
文摘Grey cast iron’s welding itself is a complex proble m.So proper welding materials must be selected,complex welding techniques such as preheating before weldingslow cooling after welding etc,should be taken. However the carbon component in low-carbon steel is comparatively low,the carbo n of welded joint will diffuse to the low-carbon steel when it is welded with gr ey cast iron,which will cause the component of carbon greatly increased at the low-carbon steel side in HAZ,high carbon martensite and cracks will occur.If p reheating before weldingslow cooling after welding and other welding procedure are taken,the grey cast iron side can probably be qualified.But the carbon wi ll diffuse to HAZ of the low-carbon steel side more easily.Therefore after stud ying the weldabilities of grey cast iron and low-carbon steel,the author develo ped a new type of cast iron electrode considering the demands of factories’prac tices,and the welding technology test of grey cast iron and low-carbon steel ar e carried out. In this paper,a new type of grey cast iron electrode is developed based on the practices in factories,its ingredients and properties are introduced.The w elding tests of grey cast iron and low-carbon steel are practiced.The joint str ucture of the dissimilar metal and the appearance of weld are observed.The hard ness distribution of the welded joint is tested.The results show that the elect rode can meet the welding requirements of the grey cast iron and low-carbon stee l.There are no cracksgas pores and other defects of metallurgy in welded join t,the appearance of welded joint are good.
基金Project(51277063) supported by the National Natural Science Foundation of ChinaProject(51407013) supported in part by the National Natural Science Foundation of China
文摘The mechanism of gas discharge in refrigeration temperature range is still not clear. N2, CF4, 20% CF4＋N2 and 50%CF4＋50%N2 binary gas mixtures were tested under the conditions of –153–25 ℃ and 50–2000 Pa. The experimental results show that the minimum of Paschen curves of all test samples shifts to low pressure, from 500 Pa to 200 Pa. The value of Paschen curve minimum of N2 shows remarkable fluctuation. This fluctuation is explained by molecule agglomeration and electronic mean energy. The fluctuation decreases with the increasing mixing ratio of CF4. What’s more, the value of Paschen curve minimum of CF4 decreases with temperature. This phenomenon is ascribed to attach-radiation and secondary process.
