Impact of light-weight external thermal insulation materials on building surrounding thermal environment in summer

The method for calculating wall surface heat storage coefficient was introduced,and the coefficients of several common walls with light-weight external thermal insulation materials and the traditional solid clay brick wall were calculated.In order to study the impact of light-weight external thermal insulation materials,a contrasting experiment was carried out between an external insulated room and an uninsulated room in August,2010,in Chongqing,China.The result shows that outside surface heat storage coefficient of the insulated wall is much less than that of the traditional wall.However,during sunny time,the surface temperature of external walls of the insulated room is obviously higher than that of the uninsulated room.In different orientations,due to different amounts of solar radiation and being irradiated in different time,the contrasting temperature difference(CTD) appears different regularity.In a word,using light-weight external thermal insulation materials has a negative impact on building surrounding thermal environment and people's health.Finally,some suggestions on how to eliminate the impact,such as improving the surface condition of the building envelop,and plating vertical greening,are put forward.

Heavy metals pollution in water,suspended matter and surface sediment in typical mountainous urban river:A case study in Qingshui Stream in Chongqing,China

Based on a detailed environmental investigation of the whole Qingshui Stream catchments,samples of water and surface sediments were collected at 15 different places from the upper to the lower reaches of Qingshui Stream,and samples of suspended matter were obtained by filtrating the water samples. The concentrations of heavy metals (Cd,Cu and Zn) were measured in filtered water,suspended matter,and surface sediment by ICP-AES. The results show that the concentrations of the three heavy metals in filtered water are 0.18,6.6 and 17.67 μg/L,lower than that of the Fresh Water Quality Criteria (US EPA) and those of the plain urban rivers,but the contents of Cd,Cu and Zn are much higher than the mean values of rivers in the world and the background value in Jialing River basin. The heavy metals concentrations in the suspended matter from Qingshui Stream are 2.08,438.14 and 1 348.05 mg/kg,much higher than the corresponding background values of soils in Chongqing city. The heavy metals concentrations in the surface sediment from Qingshui Stream are 0.84,189.75 and 838.23 mg/kg,and the values of index of geoaccumulation Igeo of Cd,Cu and Zn show that their pollution degrees are moderate. The heavy metals exist in three transferable forms such as water,suspended matter and surface sediment in Qingshui Stream. The heavy metals concentrations in water are the lowest,and those in the suspended matter are the highest,so the ecological risk in suspended matter is the highest. The distribution tendencies of three metals in water,suspended matter and surface sediment in main riverbed are different.

Nitrogen removal efficiency of iron-carbon micro-electrolysis system treating high nitrate nitrogen organic pharmaceutical wastewater

The nitrate nitrogen removal efficiency of iron-carbon micro-electrolysis system was discussed in treating pharmaceutical wastewater with high nitrogen and refractory organic concentration. The results show that the granularity of fillings,pH,volume ratios of iron-carbon and gas-water,and HRT. have significant effects on the nitrogen removal efficiency of iron-carbon micro-electrolysis system. The iron-carbon micro-electrolysis system has a good removal efficiency of pharmaceutical wastewater with high nitrogen and refractory organic concentration when the influent TN,NH4+-N,NO3--N and BOD5/CODCr are 823 mg/L,30 mg/L,793 mg/L and 0.1,respectively,at the granularity of iron and carbon 0.425 mm,pH 3,iron-carbon ratio 3,gas-water ratio 5,HRT 1.5 h,and the removal rates of TN,NH4+-N and NO3--N achieve 51.5%,70% and 50.94%,respectively.

Characterization and coagulation performance of polymeric phosphate ferric sulfate on eutrophic water

Polymeric phosphate ferric sulfate (PPFS),a new improved coagulation reagent,was prepared by polymeric ferric sulfate (PFS),Na2HPO4 and NaOH. The degree of iron polymerisation (Fepol) of PPFS was determined by means of the ferron-timed spectroscopy method. Furthermore,the effect of n(P)/n(Fe),alkalization degree,pH value,and PPFS dosage on the removal rate of eutrophic water turbidity and chl-a and ζ-potential of products were also investigated. The experimental results show that the best n(P)/n(Fe) of flocculation effect in stable product of PFFS is 0.3; the best alkalization degree of flocculation effect is 0.2,while the n(P)/n(Fe) is 0.3. Under the neutral and subalkalic (pH value is 7-8) conditions,PPFS achieves the best processing efficiency. PPFS has more excellent turbidity and higher chlorophyl removal rate by studying treatment eutrophic water in comparison with PFS.

Impact of summer office set air-conditioning temperature on energy consumption and thermal comfort

To explore the relationship between summer office set air-conditioning temperature and energy consumption related to air conditioning use to provide human thermal comfort,a comparison experiment was conducted in three similar offices at temperatures of 24,26 and 28 ℃ respectively. A thermal comfort questionnaire survey was conducted. It is demonstrated that air-conditioner energy consumption at the set temperature of 28 ℃ is 113% and 271% lower than at 26 ℃ and 24 ℃,respectively. A linear relationship exists between air-conditioner energy consumption and the indoor and outdoor temperature difference. When comfortably dressed,over 80% of research participants accept the set temperature of 28 ℃. The regression analysis leads to a neutral temperature of 26.2 ℃ and an acceptable temperature of 28.2 ℃ for over 80% of the research participants subjects,indicating that the current 26 ℃ set temperature for offices in summer,required by Chinese General Office of the State Council,can be increased to 28 ℃. Moreover,analysis of predicted mean vote(PMV) index shows that a set temperature of 27 ℃,not 26 ℃,is sufficiently comfortable for office staff wearing long-sleeve shirts,long pants and leather shoes.

Pretreatment of hypersaline mustard wastewater with integrated bioreactor

A full-scale experimental study of treating mustard wastewater by the integrated bioreactor with designed scale of 1 000 m3/d is conducted combined with a demonstration project.The systematical researches on the efficiency of combined operation conditions of anaerobic-aerobic and anaerobic-aerobic-flocculation as well as chemical phosphorus removal of hypersaline mustard wastewater are conducted.The optimal operation condition and parameters in pretreatment of mustard wastewater in winter(the water temperature ranges 8-15 ℃) are determined:the anaerobic load is 3.0 kg(COD)/(m3·d),the average COD and phosphate concentration of the inflow are respectively 3 883 mg/L and 35.53 mg/L and the dosage of flocculent(PAC) is 400 mg/L.The anaerobic-aerobic-flocculation combined operation condition and postpositive phosphorous removal with ferrous sulfate are employed.After treatment,the COD of the effluent is 470 mg/L and the average phosphate concentration is 5.09 mg/L.The effluent could achieve the third-level of Integrated Wastewater Discharge Standard(GB 8978-1996).

Removal characteristics of steroid estrogens in trickling filters

The discharge of steroid estroens from sewage treatment works (STW) is to be regulated by Environmental Quality Standard in the UK,thus requiring the understanding of removal characteristics of steroid estroens in trickling filters to benefit UK water industry with trickling filters used in 75% STWs. Two pilot-scale trickling filters were operated in parallel to treat synthetic sewage spiked with oestrone (E1),oestradiol (E2) and 17α-ethinyl oestradiol (EE2) at environmentally related concentrations. Control experiments show that biodegradation is the dominant removal mechanism although adsorption onto biofilm solids prior to biodegradation would be part of the overall mechanisms of estrogen removal. Approximately 44.7%-58.9% is removed by the pilot trickling filter normally operated,whilst the 1:1 recirculation increases 29.0%-32.2% estrogen removals by improved wetting rate and hydraulic retention time supported by tracer experiment with lithium chloride. Extra feed solids with 32.0% higher suspended solids levels inhibited estrogen removals by 10.8%-34.4% rather than helping bridge adsorption to the biofilm,and the change of particle characteristics with higher adsorption potency would benefit the removal.

Analysis and forecast of residential building energy consumption in Chongqing on carbon emissions

Carbon emissions mainly result from energy consumption. Carbon emissions inevitably will increase to some extent with economic expansion and rising energy consumption. We introduce a gray theory of quantitative analysis of the energy consumption of residential buildings in Chongqing,China,on the impact of carbon emission factors. Three impacts are analyzed,namely per capita residential housing area,domestic water consumption and the rate of air conditioner ownership per 100 urban households. The gray prediction model established using the Chongqing carbon emission-residential building energy consumption forecast model is sufficiently accurate to achieve a measure of feasibility and applicability.

Role of urban remnant evergreen broad-leaved forests on natural restoration of artificial forests in Chongqing metropolis

The effects of urban remnant natural evergreen broad-leaved forest (EBLF) on the restoration of artificial pine forests surrounding it were studied with reference to species composition,biodiversity,dominant species and stand structure on Mt. Tieshanping in Chongqing metropolis,Southwest China. The seeds from the remnant EBLF naturally facilitate the restoration process of artificial Pinus massoniana forests near it. The similarity of species composition between the artificial Pinus massoniana forests and the remnant EBLF and biodiversity index of the artificial Pinus massoniana forests decrease as the distance from the remnant EBLF increases. Castanopsis carlesii var. spinusa is the dominant species in the ground vegetation,shrub layer and sub-tree layer of the Pinus massoniana forests near the remnant EBLF. However,the natural restoration processes of those farther away from the remnant EBLF are restricted for the absence of seed source of the inherent components of the remnant EBLF,and the anthropogenic measures should be taken to facilitate the restoration process.

Field experiments on thermal comfort in university dormitories in Chongqing,China

A field study on thermal comfort was conducted in university dormitories in Chongqing,China,which was transverse with monthly from August 2008 to April 2009. A total of 1 572 returned questionnaires were collected. Thermal comfort variables were measured,at the same time students answered a survey on their indoor climate sensation. The thermal environment parameters,i.e.,indoor air temperature,air relative humidity,air velocity and outdoor air temperature were measured. The subjective survey investigated thermal sensation and preference using subjective scales. Objective data analysis shows that the indoor environments in university dormitories in Chongqing cannot meet 80% acceptability criteria prescribed by ASHRAE Standard 55. The ranges of accepted temperature are 21.5?28.5 ℃ in summer and 14.1?23.4 ℃ in winter. The preferred temperature is 22.8 ℃. It is observed that during summer season people prefer somewhat cooler condition than neutral,but in the winter season people prefer somewhat warmer condition than neutral. The relationship between air movement preference and thermal sensation indicates that even without a cooling requirement related to thermal comfort,people appear to welcome air movement.

CFD numerical simulation of dispersion law of indoor gas leakage based on weather conditions

The calculation model was established by k-ε turbulence stress which reflects the change of indoor gas leak's volume fraction,and the CFD software was used to numerically simulate the volume fraction of gas after the gas of continuity leakage,at the same time the changes of gas leak were studied. The results show that the process of gas leakage is different with the change of conditions of indoor and outdoor. Because of the different influencing factors,when the gas leak reaches a certain stable value,the volume fraction,velocity and the explosion of regional are different in the same state indoor. In some regions the gas will explode which meets the fire even if the mean volume fraction of the gas cannot achieve the explosion limit.

Techno-economic analysis of single U-tube and double U-tube heat exchangers in Chongqing area

On the basis of practical projects in Chongqing,the thermal performance of heat exchangers (single U-tube type and double U-tube type) of the ground-source heat pump (GSHP) system in the hot summer was obtained and analyzed. The data obtained from test could match with the result deduced from theoretical calculation. From the test results,the cooling capacity of double U-tube is 1.6 times that of single U-tube. Taking cost per depth per watt Clq as the evaluation standard,Clq of single U-tube is 4.69 RMB$/W,and Clq of double U-tube is 3.14 RMB$/W. The double U-tube heat exchangers usage should be prioritized.

Impact of indoor thermal comfort on physiological parameters of human body

With the living standards gradually improved,the buildings with safe,comfortable,healthy indoor thermal environment would be the ideal pursuit. But to create the preferable indoor thermal environment,it is necessary to research physiological influence of indoor thermal environment on human body. So a typical region of hot-humid climate in Chongqing,China,was considered as the object to study physiological indexes of human body. And the indoor thermal environment parameters and physiological indexes of human body were the main measurements. 20 volunteer students were organized to take part in the experiments in the laboratory during this summer. And two methods,physical measuring and questionnaire investigation,were used in the experiments. The results show that the increase in indoor air temperature reduces the uncomfortable feeling of air draft. Indoor air temperature has visible effects on MCS (motor nerve conduction speed),SCS (sensory nerve conduction speed),HR (heart rate),the ECG (electrocardiogram)-QT segment and SSEP (short somatosensory evoked potential)-latent period of N9. Therefore,a safe,comfortable and healthful indoor environment can be created by considering these factors.

Influence of landfill structures on stabilization of fully recycled leachate

The experiment was conducted to treat the leachate from two simulating columns by recycling to the columns themselves without being discharged into the enviroment. The columns were employed to simulate anaerobic and semi-aerobic landfills separately. The influence of landfill structure on stabilization of fully recycled leachate was studied. The results show that semi-aerobic landfill structure accelerates the stabilization of leachate recycled. The full recycle of leachate in semi-aerobic landfill is a very feasible and effective technology for leachate treatment with low cost and energy saving especially in arid and rare rainfall regions. Meanwhile, the environmental impact of landfill can be greatly minimized.

Forest characteristics and population structure of Glyptostrobus pensilis, a globally endangered relict species of southeastern China

The Chinese water pine Glyptostrobus pensilis is the sole surviving species of the genus Glyptostrobus. It is endemic to southern China, central Vietnam, and eastern Laos, and today it is nearly extinct in the wild. Forest community characteristics and population structure of G. pensilis in China have remained un-known up to now. We investigated six swamp forest stands and analyzed their forest community characteristics (i.e. vertical stratification, species composition, and diversity) and population structure, including the frequency distribution of DBH (diameter at breast height) and age-classes as found in Fujian Province, southeastern China. The vertical stratifications of all the forest stands were rather simple. The remaining wild specimens ranged from roughly 15 to some 357 years for an average of ca. 85 years, with only a few individuals less than 20 years old. Compared with the stands and populations of G. pensilis in Vietnam, the taxonomic compositions of the stands in the two regions were different, except for the dominant species-G. pensilis. The Shannon-Wiener index showed the overstory of each stand had much lower diversity (0.26 on average) in Fujian Province than that (1.97 on average) in Vietnam, whereas the diversity indices were about the same (around 2.41) for the understories in the two regions. Furthermore, we discovered 18 G. pensilis seedlings at the study sites in Fujian Province. This discovery demonstrates that G. pensilis regeneration is extremely poor and its populations are declining, although these populations are rela-tively healthier than those in Vietnam.

Establishment and application of performance evaluation model for collection and transportation system of municipal solid waste

On the basis of analyzing the typical waste collection and transportation mode,the evaluation index system for performance of the waste collection and transportation system was proposed with three grades,which related to six factors,such as economic evaluation,high efficient evaluation,environmental impact assessment,resource evaluation,evaluation of security and emergency,evaluation of management and society. With the performance evaluation theory,the performance evaluation model of waste collection and transportation system was constructed,which quantified the grading standard of index and determined the index weight in analytic hierarchy process (AHP). After evaluating the waste collection and transportation system of the main districts of Chongqing city,the results show that the it has an excellent performance evaluation grade with very high performance level of three indices involving evaluation of management and society,environmental impact assessment,evaluation of security and emergency and quite low performance level of two indices that include high efficient evaluation and economic evaluation.

Thermal comfort in naturally ventilated indoor environment in hot and humid climate zone in P. R. China

To identify human thermal comfort in naturally ventilated buildings,the research based on both subjective and objective data was carried out in Chongqing,P. R. China. The characteristics of subjects' clothing regulation function,changes of actual mean thermal comfort vote (AMV) varying with time and acceptable operative temperature in natural conditions were analyzed. In addition,the indicator actual mean vote-actual percentage dissatisfied (AMV-APD) was used to study the actual dissatisfaction with thermal environment. The results indicate that regulative ability by changing clothing under natural ventilated conditions is very significant but limited simultaneously,about 1.7 ℃ per 0.1 clo. Under naturally ventilated conditions,people may have an acceptable operative temperature of 16-28 ℃. Based on the AMV-APD,the actual minimum percentage dissatisfied can reach 4% at AMV of -0.36.

Applicability of sewage heat pump air-conditioning system

A sewage heat pump system and its application based on a project in Chongqing,China,were discussed. Based on the sewage conditions,a feasibility analysis of the sewage heat pump air conditioning system was conducted. The theoretical and quantitative calculations indicate that sewage flux in the city sewage main pipe in the project can satisfy heat exchange requirements,and taking water from the pipes has relatively small influence on the pipe net in summer and winter. The sewage heat pump air-conditioning system can save 21.5% operating cost in one year,which is energy efficient and environmentally friendly.

Method for acquiring part load distribution coefficient of air conditioning system

This paper presents a method to acquire runtime distribution ratio of building air conditioning system under part load condition (part load coefficient of system) through practical energy consumption data. By utilizing monthly energy consumption data of the entire year as the analysis object,this paper identifies data distribution,verifies distribution characteristics and analyzes distribution probability density for the issue of running time distribution ratio of air conditioning system in part load zones in the whole operation period,thus providing a basic calculation basis for an overall analysis of energy efficiency of air conditioning system. In view of the general survey of public building energy consumption carried by the government of Chongqing,this paper takes the governmental office building as an example,the part load ratio coefficient corresponding to practical running of air conditioning system of governmental office building in Chongqing is obtained by utilizing the above probability analysis and the solving method of probability density function. By utilizing the ratio coefficient obtained using this method,the part load coefficient with any running ratio of air conditioning system can be obtained according to the requirement of analysis,which can be used in any load ratio for analyzing running energy efficiency of air conditioning system.

Thermal environment analysis of mountainous towns based on GIS

Outdoor thermal environment prediction and evaluation system was established based on a geographic information system. The system uses digital elevation model data and satellite imagery of mountainous towns. The system can conveniently provide a three-dimensional view of a town as well as predict the urbanization rate and urban heat island intensity. In addition,the system also permits quick inquiry and analysis of the temperature field,moisture field,and wind field tendency and current conditions of towns. The system was tested using the town of Yunyang,Chongqing Municipality,China,as a case study. The system was used to analyze and predict the climate comfort of the entire town and the outdoor thermal environment comfort of certain town districts,squares and streets. The results are in accordance with the measured data. This outdoor thermal environment prediction and evaluation method thus can provide a feasible reference for the general plan of mountainous town and promote the sustainable development of mountainous towns.