The thermal-environment characteristics of the existing forced-convection cooling system were compared with those of the convective cooling system, which combined the radiant-floor cooling system using floor-heating p...The thermal-environment characteristics of the existing forced-convection cooling system were compared with those of the convective cooling system, which combined the radiant-floor cooling system using floor-heating panel typically applied to apartments in South Korea with the forced-convection cooling system using improved fan coil unit. The subjective warm/cool-feeling responses to the combined radiant-floor and convective cooling system in the questionnaire survey conducted among the test subjects were analyzed to establish the basic data for the combined cooling system. The results show that in the thermal-equilibrium condition, the vertical air temperature difference in the model living room is larger in the forced-convection-cooling condition. Most of the subjects feel a proper warm/cool feeling on their entire body, but they feel colder on the foot and lower body in the combined-cooling condition.展开更多
A tool was developed to assist the cooling systems designer in designing and installing the microsprinklers and fan cooling system. The tool was developed by integrating a mathematical model into an electronic spark m...A tool was developed to assist the cooling systems designer in designing and installing the microsprinklers and fan cooling system. The tool was developed by integrating a mathematical model into an electronic spark map in order to use the mathematical model practically. The mathematical model was developed using the designs, parameters, variables, and constant values of the microsprinklers and fans cooling system. Subsequently, an electronic spark map （decision tree） was developed, and then the mathematical model was integrated into the electronic spark map. Afterwards, C# （C Sharp） programming language was used to develop a computer system via the electronic spark map, and to make the user interface. The developed computer system assists the designer in making decisions to specify and to calculate the required discharge of cooling system pump, length and diameter of cooling system pipelines, number of cooling fans, and number of microsprinklers. Moreover, this tool calculates the capital investment and the fixed, variable, and total costs of the cooling system. However, the mathematical model of the spark map requires some input data such as： pressure and discharge of microsprinklers, and some other engineering parameters. Data of 4 cooling systems were used to carry out the model validation. The differences between actual and calculated values were determined, and the standard deviations were calculated. The coefficients of variation were between 2.25% and 4.13%.展开更多
Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipmen...Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipment is necessary. But it is difficult to evaluate it reasonably and comprehensively due to its complexity. A "holistic" approach was discussed to evaluate the energy performance of central air-conditioning system for an extra-large commercial building in a subtropical city. All procedures were described in detail, including field investigation method, field measurement instruments, data processing and data analyzing. The main factors affecting energy consumption of air-conditioning system were analyzed and the annual cooling-energy use intensity of this building was calculated and also compared with other shopping malls and other types of buildings in Guangzhou. And COP(coefficient of performance) of chiller, water transfer factor of chilled water system and cooling water system were taken into consideration. At last, the thermal comfort and indoor air quality issues were addressed. The results show that the chilled water pumps are over-sized and the indoor environmental quality should be improved. The purpose of this work is to provide reference for energy performance assessment method for air-conditioning system.展开更多
The Xiashu loess is a typical Quaternary eolian deposit in southem China and represents an important terrestrial paleoclimate archive in this low-latitude monsoon region. However, the chronological framework of Xiashu...The Xiashu loess is a typical Quaternary eolian deposit in southem China and represents an important terrestrial paleoclimate archive in this low-latitude monsoon region. However, the chronological framework of Xiashu loess deposition has yet to be established. Determining the timing of the onset of Xiashu loess deposition will allow researchers to better understand late Quaternary aridification across the Asian continent, the evolution of the East Asian monsoon and regional environmental changes in subtropical regions. Therefore, in this study, a systematic chronological study of the Xiashu loess is conducted to answer this question. For the first time, magnetostratigraphic classification reveals that the Matuyama/Bnmhes （M/B） reversal is present in the Xiashu loess at two sites in Jiangsu Province, the Qingshan profile at Yizheng and the Dagang core in Zhenjiang. Based on the results of magnetostratigraphy and optically stimulated luminescence （OSL） dating, the age of the lower boundary of the Xiashu loess is estimated to be approximately 0.9 Ma. Consequently, this Xiashu loess deposit is the oldest reported to date and is comparable in age to the red soil deposit in Xuancheng, Anhui Province. The onset of Xiashu loess deposition by 0.9 Ma represents the further expansion of arid range in Asia in the late Quaternary in response to significant aridification and winter monsoon strengthening in this subtropical region. We suggest that these climate changes were primarily driven by global cooling and an increase in high-latitude ice volume in the Northern Hemisphere and that the initiation of Xiashu loess accumulation was a regional response of southern China to the 0.9 Ma global cooling event.展开更多
基金Project(NRF-2013RIA2A1A01014020)supported by the National Research Foundation of Korea
文摘The thermal-environment characteristics of the existing forced-convection cooling system were compared with those of the convective cooling system, which combined the radiant-floor cooling system using floor-heating panel typically applied to apartments in South Korea with the forced-convection cooling system using improved fan coil unit. The subjective warm/cool-feeling responses to the combined radiant-floor and convective cooling system in the questionnaire survey conducted among the test subjects were analyzed to establish the basic data for the combined cooling system. The results show that in the thermal-equilibrium condition, the vertical air temperature difference in the model living room is larger in the forced-convection-cooling condition. Most of the subjects feel a proper warm/cool feeling on their entire body, but they feel colder on the foot and lower body in the combined-cooling condition.
文摘A tool was developed to assist the cooling systems designer in designing and installing the microsprinklers and fan cooling system. The tool was developed by integrating a mathematical model into an electronic spark map in order to use the mathematical model practically. The mathematical model was developed using the designs, parameters, variables, and constant values of the microsprinklers and fans cooling system. Subsequently, an electronic spark map （decision tree） was developed, and then the mathematical model was integrated into the electronic spark map. Afterwards, C# （C Sharp） programming language was used to develop a computer system via the electronic spark map, and to make the user interface. The developed computer system assists the designer in making decisions to specify and to calculate the required discharge of cooling system pump, length and diameter of cooling system pipelines, number of cooling fans, and number of microsprinklers. Moreover, this tool calculates the capital investment and the fixed, variable, and total costs of the cooling system. However, the mathematical model of the spark map requires some input data such as： pressure and discharge of microsprinklers, and some other engineering parameters. Data of 4 cooling systems were used to carry out the model validation. The differences between actual and calculated values were determined, and the standard deviations were calculated. The coefficients of variation were between 2.25% and 4.13%.
基金Project(2011B061200043)supported by the Guangdong Provincial Department of Science and Technology,China
文摘Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipment is necessary. But it is difficult to evaluate it reasonably and comprehensively due to its complexity. A "holistic" approach was discussed to evaluate the energy performance of central air-conditioning system for an extra-large commercial building in a subtropical city. All procedures were described in detail, including field investigation method, field measurement instruments, data processing and data analyzing. The main factors affecting energy consumption of air-conditioning system were analyzed and the annual cooling-energy use intensity of this building was calculated and also compared with other shopping malls and other types of buildings in Guangzhou. And COP(coefficient of performance) of chiller, water transfer factor of chilled water system and cooling water system were taken into consideration. At last, the thermal comfort and indoor air quality issues were addressed. The results show that the chilled water pumps are over-sized and the indoor environmental quality should be improved. The purpose of this work is to provide reference for energy performance assessment method for air-conditioning system.
基金supported by the National Natural Science Foundation of China(Grant Nos.41571188,41671191,41690111&40971004)
文摘The Xiashu loess is a typical Quaternary eolian deposit in southem China and represents an important terrestrial paleoclimate archive in this low-latitude monsoon region. However, the chronological framework of Xiashu loess deposition has yet to be established. Determining the timing of the onset of Xiashu loess deposition will allow researchers to better understand late Quaternary aridification across the Asian continent, the evolution of the East Asian monsoon and regional environmental changes in subtropical regions. Therefore, in this study, a systematic chronological study of the Xiashu loess is conducted to answer this question. For the first time, magnetostratigraphic classification reveals that the Matuyama/Bnmhes （M/B） reversal is present in the Xiashu loess at two sites in Jiangsu Province, the Qingshan profile at Yizheng and the Dagang core in Zhenjiang. Based on the results of magnetostratigraphy and optically stimulated luminescence （OSL） dating, the age of the lower boundary of the Xiashu loess is estimated to be approximately 0.9 Ma. Consequently, this Xiashu loess deposit is the oldest reported to date and is comparable in age to the red soil deposit in Xuancheng, Anhui Province. The onset of Xiashu loess deposition by 0.9 Ma represents the further expansion of arid range in Asia in the late Quaternary in response to significant aridification and winter monsoon strengthening in this subtropical region. We suggest that these climate changes were primarily driven by global cooling and an increase in high-latitude ice volume in the Northern Hemisphere and that the initiation of Xiashu loess accumulation was a regional response of southern China to the 0.9 Ma global cooling event.
