Presented a new coal dust control program that was airtight negative pressure dust-control technology at the transpersite,combining with analysis with the movement of air currents and numerical simulation of gas-solid...Presented a new coal dust control program that was airtight negative pressure dust-control technology at the transpersite,combining with analysis with the movement of air currents and numerical simulation of gas-solid flow at the transpersite,and proved the mechanism of precipitation and proliferation for coal dust-controlt in theory.The technol- ogy has made good economic results at the Heidaigou Clean Plant,not only dust concen- tration control within 10 mg/m^3 to the work site,but also substantial energy savings and cost savings.展开更多
Road tunnel excavation often traverses coal strata, which is at risk of firedamp explosion that usually results in disaster. Airtight concrete grouting is popularly used in this kind of tunnel project. Based on the es...Road tunnel excavation often traverses coal strata, which is at risk of firedamp explosion that usually results in disaster. Airtight concrete grouting is popularly used in this kind of tunnel project. Based on the essential theory of mechanics of fluids in porous media, the principle of improving concrete airtight property and its influential factors are investigated. The proportioning tests and monitoring method for airtight concrete are introduced, which is illustrated by a case study applied to the project of the Huayinshan Tunnel. It is proved by engineering practices that the achievement of this research work is beneficial to tunneling project across coal strata.展开更多
Zero-energy buildings constitute an effective means of reducing urban carbon emissions.High airtightness,a typical characteristic of zero-energy building,is closely related to the building’s air infiltration and has ...Zero-energy buildings constitute an effective means of reducing urban carbon emissions.High airtightness,a typical characteristic of zero-energy building,is closely related to the building’s air infiltration and has a signifi-cant impact on the performance of the building envelope,indoor air quality,building energy consumption,and efficient operation of air-conditioning systems.However,thus far,systematic developments in high-airtightness assurance technologies remain scarce.Most existing studies have tested the airtightness of buildings and typical building components;however,in-depth analyses into the formation of infiltration have not been reported.There-fore,for realizing zero-energy buildings,ensuring airtightness is an urgent problem that needs to be addressed.Accordingly,in this study,based on several building airtightness measurement studies,the typical air leakage paths in buildings were summarized,and the causes of typical air leakage components in buildings were further analysed by tracing construction processes.Moreover,targeted measures for airtightness in buildings were estab-lished and applied to practical cases.Lastly,the resulting improved building airtightness was measured and the results show that the airtightness of the measured ultra-low energy consumption buildings ranges from 0.13 h^(−1)to 0.57 h^(−1),with a mean value of 0.32 h^(−1).The effectiveness of the airtightness safeguard measures was verified.This study serves as a basis for the assumption of the air leakage path distribution when simulating building air infiltration and also provides a design reference for improving the construction technologies and airtightness of buildings.展开更多
Air infiltration through building envelopes has a considerable impact on the comprehensive performance of build-ings,especially in terms of their energy demand and indoor air quality.Therefore,it is important to accur...Air infiltration through building envelopes has a considerable impact on the comprehensive performance of build-ings,especially in terms of their energy demand and indoor air quality.Therefore,it is important to accurately predict building air infiltration rates under various scenarios.High airtightness is one of the typical character-istics of passive ultra-low energy buildings.With the rapid application of passive technology in building energy efficiency,the airtightness of new urban buildings has been significantly improved.The centralized air leakage path distribution assumption of current prediction model for building air infiltration rate is inconsistent with the actual situation of high airtightness buildings,which reduces its prediction accuracy and application range.Therefore,it is of great practical significance and academic value to carry out the research on the prediction model of air infiltration rate of buildings with high airtightness.This paper presents an air infiltration prediction model for single-zone buildings with adventitious openings.The building envelope was broken down into permeable parts and impermeable parts,and the air leakage path-ways were assumed to be uniformly and continuously distributed in the permeable envelope.A linear pressure distribution over the building facade was assumed,and the airflow rate was integrated in the vertical and hori-zontal planes to theoretically predict the air infiltration rate.The feasibility of the proposed model was tested by comparing the air infiltration rates simulated by this model with those determined using the tracer gas attenua-tion method of an airtight building.The initial test results suggest that this model is mathematically robust and is capable of modeling the air infiltration of a building in a wide variety of scenarios.Reasonable agreement was found between the tested and simulated results.This study can provide basic theoretical support for the coupling performance analysis of high airtightness buildings.展开更多
文摘Presented a new coal dust control program that was airtight negative pressure dust-control technology at the transpersite,combining with analysis with the movement of air currents and numerical simulation of gas-solid flow at the transpersite,and proved the mechanism of precipitation and proliferation for coal dust-controlt in theory.The technol- ogy has made good economic results at the Heidaigou Clean Plant,not only dust concen- tration control within 10 mg/m^3 to the work site,but also substantial energy savings and cost savings.
基金Funded by the Doctoral Foundation of the Ministry of Education of China (2000061115)
文摘Road tunnel excavation often traverses coal strata, which is at risk of firedamp explosion that usually results in disaster. Airtight concrete grouting is popularly used in this kind of tunnel project. Based on the essential theory of mechanics of fluids in porous media, the principle of improving concrete airtight property and its influential factors are investigated. The proportioning tests and monitoring method for airtight concrete are introduced, which is illustrated by a case study applied to the project of the Huayinshan Tunnel. It is proved by engineering practices that the achievement of this research work is beneficial to tunneling project across coal strata.
基金the Natural Science Foundation of Shandong Province Youth Project(Grant no.ZR2020QE224).
文摘Zero-energy buildings constitute an effective means of reducing urban carbon emissions.High airtightness,a typical characteristic of zero-energy building,is closely related to the building’s air infiltration and has a signifi-cant impact on the performance of the building envelope,indoor air quality,building energy consumption,and efficient operation of air-conditioning systems.However,thus far,systematic developments in high-airtightness assurance technologies remain scarce.Most existing studies have tested the airtightness of buildings and typical building components;however,in-depth analyses into the formation of infiltration have not been reported.There-fore,for realizing zero-energy buildings,ensuring airtightness is an urgent problem that needs to be addressed.Accordingly,in this study,based on several building airtightness measurement studies,the typical air leakage paths in buildings were summarized,and the causes of typical air leakage components in buildings were further analysed by tracing construction processes.Moreover,targeted measures for airtightness in buildings were estab-lished and applied to practical cases.Lastly,the resulting improved building airtightness was measured and the results show that the airtightness of the measured ultra-low energy consumption buildings ranges from 0.13 h^(−1)to 0.57 h^(−1),with a mean value of 0.32 h^(−1).The effectiveness of the airtightness safeguard measures was verified.This study serves as a basis for the assumption of the air leakage path distribution when simulating building air infiltration and also provides a design reference for improving the construction technologies and airtightness of buildings.
基金The authors are grateful to the Shandong Provincial Natural Science Foundation(ZR2020QE224)National Natural Science Foundation of China(NO:52108079)+1 种基金Open Fund of innovation institute for Sustain-able Maritime Architecture Research and Technology(iSMART)(Grant no.2020-011)the National Key R&D Program of China Technical System and Key Technology Development of Nearly Zero Energy Build-ing(Grant no.2017YFC0702601).
文摘Air infiltration through building envelopes has a considerable impact on the comprehensive performance of build-ings,especially in terms of their energy demand and indoor air quality.Therefore,it is important to accurately predict building air infiltration rates under various scenarios.High airtightness is one of the typical character-istics of passive ultra-low energy buildings.With the rapid application of passive technology in building energy efficiency,the airtightness of new urban buildings has been significantly improved.The centralized air leakage path distribution assumption of current prediction model for building air infiltration rate is inconsistent with the actual situation of high airtightness buildings,which reduces its prediction accuracy and application range.Therefore,it is of great practical significance and academic value to carry out the research on the prediction model of air infiltration rate of buildings with high airtightness.This paper presents an air infiltration prediction model for single-zone buildings with adventitious openings.The building envelope was broken down into permeable parts and impermeable parts,and the air leakage path-ways were assumed to be uniformly and continuously distributed in the permeable envelope.A linear pressure distribution over the building facade was assumed,and the airflow rate was integrated in the vertical and hori-zontal planes to theoretically predict the air infiltration rate.The feasibility of the proposed model was tested by comparing the air infiltration rates simulated by this model with those determined using the tracer gas attenua-tion method of an airtight building.The initial test results suggest that this model is mathematically robust and is capable of modeling the air infiltration of a building in a wide variety of scenarios.Reasonable agreement was found between the tested and simulated results.This study can provide basic theoretical support for the coupling performance analysis of high airtightness buildings.
