The energy efficiency design of the exterior wall in the buildings of the hot summer and cold winter zone of China should consider the heat prevention in summer and the heat insulation in winter. The self-insulation o...The energy efficiency design of the exterior wall in the buildings of the hot summer and cold winter zone of China should consider the heat prevention in summer and the heat insulation in winter. The self-insulation of the exterior?wall is a more feasible design to satisfy the energy efficiency of buildings in the?zone. However, the systematic research is urgently needed for the self-insulation of the exterior wall in the hot summer and cold winter zone of China. The paper tested the thermal performance of the common non-clay materials such as shale sintered hollow brick, sand autoclaved aerated concrete block, etc. by means of indoor experiments. The energy efficiency effect of the common materials was verified using dynamic calculation soft PKPM and several constitutions of exterior wall with different main bricks and insulation materials on the heat bridge were simulated, too. Besides, the tests of the thermal performance of exterior wall in real constructions were carried out to testify the practical effect of the recommended constitutions of exterior wall with different main bricks and insulation materials on the heat bridge. The conclusions are: the physical and thermal properties of the six non-clay wall material are better than the clay porous brick;the thermal performance of the non-clay brick can be improved obviously through the rational arrangement of the holes;shale sintered hollow brick after increasing the holes and rationalizing the hole arrangement and sand autoclaved aerated concrete block are recommended for buildings in the hot summer and cold winter area of China. The dynamic calculation results show that the thermal performances?of the non-clay materials are all satisfied with the energy efficiency;The heat transfer coefficient of the exterior wall with composition?③,?in which?the main wall was sand autoclaved aerated concrete block and the material on the heat bridge was sand autoclaved aerated concrete plate, is the smallest among the three recommended compositions.展开更多
When one applies the wavelet transform to analyze finite-length time series, discontinuities at the data boundaries will distort its wavelet power spectrum in some regions which are defined as a wavelength-dependent c...When one applies the wavelet transform to analyze finite-length time series, discontinuities at the data boundaries will distort its wavelet power spectrum in some regions which are defined as a wavelength-dependent cone of influence （COI）. In the COI, significance tests are unreliable. At the same time, as many time series are short and noisy, the COI is a serious limitation in wavelet analysis of time series. In this paper, we will give a method to reduce boundary effects and discover significant frequencies in the COI. After that, we will apply our method to analyze Greenland winter temperature and Baltic sea ice. The new method makes use of line removal and odd extension of the time series. This causes the derivative of the series to be continuous （unlike the case for other padding methods）. This will give the most reasonable padding methodology if the time series being analyzed has red noise characteristics.展开更多
随着电动汽车行业的迅猛发展,消费者对车内热舒适性的要求日益提高。然而,汽车空调系统的能耗显著降低了电动汽车的续航里程,这一问题在冬季尤为突出。本研究旨在通过实车路试,监测不同运行条件下热泵空调系统的表现,评估汽车热泵空调...随着电动汽车行业的迅猛发展,消费者对车内热舒适性的要求日益提高。然而,汽车空调系统的能耗显著降低了电动汽车的续航里程,这一问题在冬季尤为突出。本研究旨在通过实车路试,监测不同运行条件下热泵空调系统的表现,评估汽车热泵空调系统在冬季低温环境下的性能,并对比正温度系数加热器(Positive Temperature Coefficient Heater,PTC)与热泵两种制热技术在加热过程中的能耗表现。结果表明,热泵空调系统能够在5~12 min内快速响应并达到设定温度,运行过程中温度波动控制在±2℃以内,显示出良好的温度控制性能。在相同工况下,热泵技术相较于PTC展现出显著的节能优势,能耗约为PTC的1/2。研究成果对汽车行业提升产品竞争力和响应节能减排号召具有重要的实践价值,也为未来电动汽车空调系统的设计与改进指明了方向。展开更多
文摘The energy efficiency design of the exterior wall in the buildings of the hot summer and cold winter zone of China should consider the heat prevention in summer and the heat insulation in winter. The self-insulation of the exterior?wall is a more feasible design to satisfy the energy efficiency of buildings in the?zone. However, the systematic research is urgently needed for the self-insulation of the exterior wall in the hot summer and cold winter zone of China. The paper tested the thermal performance of the common non-clay materials such as shale sintered hollow brick, sand autoclaved aerated concrete block, etc. by means of indoor experiments. The energy efficiency effect of the common materials was verified using dynamic calculation soft PKPM and several constitutions of exterior wall with different main bricks and insulation materials on the heat bridge were simulated, too. Besides, the tests of the thermal performance of exterior wall in real constructions were carried out to testify the practical effect of the recommended constitutions of exterior wall with different main bricks and insulation materials on the heat bridge. The conclusions are: the physical and thermal properties of the six non-clay wall material are better than the clay porous brick;the thermal performance of the non-clay brick can be improved obviously through the rational arrangement of the holes;shale sintered hollow brick after increasing the holes and rationalizing the hole arrangement and sand autoclaved aerated concrete block are recommended for buildings in the hot summer and cold winter area of China. The dynamic calculation results show that the thermal performances?of the non-clay materials are all satisfied with the energy efficiency;The heat transfer coefficient of the exterior wall with composition?③,?in which?the main wall was sand autoclaved aerated concrete block and the material on the heat bridge was sand autoclaved aerated concrete plate, is the smallest among the three recommended compositions.
基金partially supported by the National Key Science Program for Global Change Research (Grant no.2010CB950504)the National High-Technology Research & Development Program of China (863 Program,Grant no.2010AA012305)+2 种基金the National Natural Science Foundation of China(Grant no.41076125)the Fundamental Research Funds for the Central Universities (Key Program)the Polar Climate and Environment Key Laboratory
文摘When one applies the wavelet transform to analyze finite-length time series, discontinuities at the data boundaries will distort its wavelet power spectrum in some regions which are defined as a wavelength-dependent cone of influence （COI）. In the COI, significance tests are unreliable. At the same time, as many time series are short and noisy, the COI is a serious limitation in wavelet analysis of time series. In this paper, we will give a method to reduce boundary effects and discover significant frequencies in the COI. After that, we will apply our method to analyze Greenland winter temperature and Baltic sea ice. The new method makes use of line removal and odd extension of the time series. This causes the derivative of the series to be continuous （unlike the case for other padding methods）. This will give the most reasonable padding methodology if the time series being analyzed has red noise characteristics.
文摘随着电动汽车行业的迅猛发展,消费者对车内热舒适性的要求日益提高。然而,汽车空调系统的能耗显著降低了电动汽车的续航里程,这一问题在冬季尤为突出。本研究旨在通过实车路试,监测不同运行条件下热泵空调系统的表现,评估汽车热泵空调系统在冬季低温环境下的性能,并对比正温度系数加热器(Positive Temperature Coefficient Heater,PTC)与热泵两种制热技术在加热过程中的能耗表现。结果表明,热泵空调系统能够在5~12 min内快速响应并达到设定温度,运行过程中温度波动控制在±2℃以内,显示出良好的温度控制性能。在相同工况下,热泵技术相较于PTC展现出显著的节能优势,能耗约为PTC的1/2。研究成果对汽车行业提升产品竞争力和响应节能减排号召具有重要的实践价值,也为未来电动汽车空调系统的设计与改进指明了方向。
