A research on the heat transfer performance of kerosene flowing in a vertical upward tube at supercritical pressure is presented.In the experiments,insights are offered on the effects of the factors such as mass flux,...A research on the heat transfer performance of kerosene flowing in a vertical upward tube at supercritical pressure is presented.In the experiments,insights are offered on the effects of the factors such as mass flux,heat flux,and pressure.It is found that increasing mass flux reduces the wall temperature and separates the experimental section into three different parts,while increasing working pressure deteriorates heat transfer.The extended corresponding-state principle can be used for evaluating density and transport properties of kerosene,including its viscosity and thermal conductivity,at different temperatures and pressures under supercritical conditions.For getting the heat capacity,a Soave–Redlich–Kwong(SRK)equation of state is used.The correlation for predicting heat transfer of kerosene at supercritical pressure is established and shows good agreement with the experimental data.展开更多
To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and pre...To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and presents a new on-line self-flushing technique, which alternately flushes part of heat transfer tubes. In addition, operation principles and the structure of the new heat-exchanger are introduced and the feasible economi- cal and technological cleaning plans are given by design calculation and scheme comparison. The result shows that keeping each tube washed for one minute with 5 m/s, the operating cost is lower than ￥5 and when one flushing pump ahemately flushes 10-20 heat exchangers, the saved costs of flushing 10 tubes alternately are over 4 times of the increased costs.展开更多
As one of the key units of space CCD camera,the temperature range and stability of CCD components affect the image's indexes.Reasonable thermal design and robust thermal control devices are needed.One kind of temp...As one of the key units of space CCD camera,the temperature range and stability of CCD components affect the image's indexes.Reasonable thermal design and robust thermal control devices are needed.One kind of temperature control loop heat pipe(TCLHP) is designed,which highly meets the thermal control requirements of CCD components.In order to study the dynamic behaviors of heat and mass transfer of TCLHP,particularly in the orbital flight case,a transient numerical model is developed by using the well-established empirical correlations for flow models within three dimensional thermal modeling.The temperature control principle and details of mathematical model are presented.The model is used to study operating state,flow and heat characteristics based upon the analyses of variations of temperature,pressure and quality under different operating modes and external heat flux variations.The results indicate that TCLHP can satisfy the thermal control requirements of CCD components well,and always ensure good temperature stability and uniformity.By comparison between flight data and simulated results,it is found that the model is to be accurate to within 1℃.The model can be better used for predicting and understanding the transient performance of TCLHP.展开更多
基金Supported by the National Science Foundation of Zhejiang Province(Z13E060001)the National Natural Science Foundation of China(52176091)+1 种基金the National Science Foundation of Shandong Province(ZR2012EEQ017)the PhD Program Foundation of Ministry of Education of China(20120101110102)
文摘A research on the heat transfer performance of kerosene flowing in a vertical upward tube at supercritical pressure is presented.In the experiments,insights are offered on the effects of the factors such as mass flux,heat flux,and pressure.It is found that increasing mass flux reduces the wall temperature and separates the experimental section into three different parts,while increasing working pressure deteriorates heat transfer.The extended corresponding-state principle can be used for evaluating density and transport properties of kerosene,including its viscosity and thermal conductivity,at different temperatures and pressures under supercritical conditions.For getting the heat capacity,a Soave–Redlich–Kwong(SRK)equation of state is used.The correlation for predicting heat transfer of kerosene at supercritical pressure is established and shows good agreement with the experimental data.
基金Sponsored by the National Natural Science Foundation of China (Grant No.50578048)
文摘To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and presents a new on-line self-flushing technique, which alternately flushes part of heat transfer tubes. In addition, operation principles and the structure of the new heat-exchanger are introduced and the feasible economi- cal and technological cleaning plans are given by design calculation and scheme comparison. The result shows that keeping each tube washed for one minute with 5 m/s, the operating cost is lower than ￥5 and when one flushing pump ahemately flushes 10-20 heat exchangers, the saved costs of flushing 10 tubes alternately are over 4 times of the increased costs.
文摘As one of the key units of space CCD camera,the temperature range and stability of CCD components affect the image's indexes.Reasonable thermal design and robust thermal control devices are needed.One kind of temperature control loop heat pipe(TCLHP) is designed,which highly meets the thermal control requirements of CCD components.In order to study the dynamic behaviors of heat and mass transfer of TCLHP,particularly in the orbital flight case,a transient numerical model is developed by using the well-established empirical correlations for flow models within three dimensional thermal modeling.The temperature control principle and details of mathematical model are presented.The model is used to study operating state,flow and heat characteristics based upon the analyses of variations of temperature,pressure and quality under different operating modes and external heat flux variations.The results indicate that TCLHP can satisfy the thermal control requirements of CCD components well,and always ensure good temperature stability and uniformity.By comparison between flight data and simulated results,it is found that the model is to be accurate to within 1℃.The model can be better used for predicting and understanding the transient performance of TCLHP.
