Abstract:Outdoor PM2.5 could penetrate through fresh air and the wall gap into the room especially when outdoor PM2.5 is particularly high, which lead to the rapid rise in the indoor PM2.5 concentration. To determine the influence of the air conditioning system form on the indoor and outdoor PM2.5 concentration, the PM2.5 concentration in the room with different air conditioning forms is measured in the summer of 2015, which is in an office building in Chongqing. The measured results show that: the range of the indoor and outdoor PM2.5 concentration ratio is 0.59～0.76,0.47～0.76,and 0.71～0.91, respectively when the air conditioning system is. The relationship of indoor and outdoor PM2.5 concentration correlation coefficient is centralized air conditioning environment(0.94) >non air conditioning environment (0.92) > decentralized air conditioning environment (0.77).The results show that air conditioning form in office building has the effect of on indoor PM2.5 concentration.

Abstract:Clothing thermal resistance is a key factor that affects the thermal comfort of human body. The total thermal resistance of bedding and clothing system in sleeping at night includes the clothing system resistance and the body of the mattress system. In the low pressure environment, there is still a lack of experimental data and calculation model of thermal resistance, with no reference to theory models. In this paper, based on calculation method of the total thermal resistance of bedding and clothing system in sleeping, the calculation model of total thermal resistance in low pressure environment is established by the introduction of pressure correction of related parameters. The typical total thermal resistance both summer and winter is calculated using the model. The variation rules of total thermal resistance caused by the pressure reducing is obtained. At altitude of less than 3000m, the increasing coefficient of total thermal resistance of bedding and clothing system caused by the coverage ratio of blanket is not more than 0.05. The total thermal resistances both winter and summer increase with atmospheric pressure decreasing. There is a same maximum percentage of 42% under the condition of 23.3% of blanket coverage.

Abstract:This study focuses on thermal comfort of subjects with radiant panel workstation in hot-humid environment. The experiments are carried out in the experimental chamber. Thermal sensations of whole body, head, trunk, upper limb and lower limb of subjects are collected on the basis of seven-scale vote. The obtained results indicate that the average vote of thermal sensation at 28 ℃ is lower than +0.2, and subjects could maintain comfortable condition well with radiant panel workstation (within the 80% acceptable range of ASHRAE Standard) although indoor environment is as high as 30 ℃. This study provides a new way for both extending comfortable temperature range and saving energy in buildings.

Abstract:The heat transfer performance of ground heat exchangers (GHEs) is influenced by different geological structures. A three-dimensional heat transfer model of double U-type GHEs is established with typical geological structure of Wuhan and Chongqing as boundary conditions separately. The heat transfer performances are obtained through the model calculation. The simulation results are validated by a practical thermal response test of a ground source heat pump (GSHP) system, which shows a good match between the simulated and experimental results. The influence of geological structure on heat transfer performances is investigated and the heat transfer performance of GSHP systems can be predicted. Besides, the average heat transfer coefficient of GHEs is calculated in these two area with the proposed model, and the average heat transfer coefficient of the heat exchanger is K₁=1.65 (w/m.K) in Wuhan area, K₂=1.51 (w/m.K) in Chongqing area, respectively.

Abstract:Four main device models (evaporator, condenser, compressor and expansion valve) of the sewage-source heat pump were developed and coupled. The MATLAB software was used for this simulation, and the effects of fouling resistance, sewage flow and sewage inlet temperature on the heating performance of sewage-source heat pump were calculated respectively. The results revealed that while the fouling resistance changed from 0 to 1(m²·K)/kW, the heating capacity of the device was decreased from 353 kW to 301 kW, decreased by 14.8%. While the sewage inlet temperature increased from 8 to 20 ℃, the heating capacity of the device was increased from 320 kW to 423 kW, increased by 32.1%. While the sewage flow increased from 10 kg/s to 20 kg/s, the heating capacity of the device was increased from 339 kW to 364 kW. The COP of this heat pump changed from 3.6 to 4.8 in the process, which illustrated the good heating performance of the sewage source heat pump.

Abstract:In southern area of china, the problem that balancing heating load in winter with cooling load in summer to ensure indoor thermal comfort when designing building envelop still remains. In this article, the correlation between thermal characteristics of building envelope and energy load is found by analyzing dynamic thermal process of buildings in hot summer and cold(warm)winter zones. In addition, the thermal characteristics of building envelope which affect indoor thermal environment and thermal stability of building are revealed. Also, the impact mechanism of enclosure thermal performance on indoor thermal environment and thermal stability is studied. By taking the balance between winter heat preservation and summer heat dissipation into consideration, the calculation of annual building energy consumption would be carried out, based on which the existing enclosure energy-saving method is evaluated from the standpoint of energy-saving effect, safety, reliability, economy and practicability. Finally, the climatic-suitable thermal design and its structure type of the enclosure is proposed.

Abstract:Based on the analysis of winter field survey and thermal environment measurement, the buffer-space design can obviously improve indoor thermal environment in the residential buildings of Lhasa. However, the indoor winter thermal environment of non-heating rooms still need to be improved. Local people have strong heating demand for residential buildings. All the clues lead to the fast growing tendency of heating energy consumption and environmental load in Lhasa. The basic simulation models for understanding the buffer-space's effect to heating energy consumption are established from the common residential buildings in Lhasa, and the factors include south and north buffer-space's depth design. Result shows that buffer-space can obviously reduce winter heating energy consumption. Along with the south buffer-space's depth increasing, the heating energy consumption shows the tendency of continuous increasing; as for the north buffer-space, the tendency is firstly getting decreasing and then increasing, and the energy consumption among models is not large. The heating energy consumption comparison study between common model and optimal buffer-space design model shows that buffer-space design can obviously reduce the heating energy consumption.

Abstract:Sales volume on convenience stores increased the most, and lighting made up 43% of interior energy consumption. Based on sample investigation of 257 convenience stores in China, the survey data were collected, and lighting feature were exposed. Multiple linear regression was adopted to built the prediction model of lighting energy consumption, and factor analysis was adopted to explore the connection between subjective evaluation and objective variables. The results showed that: for convenience stores, subjective evaluation would be accounted when saving lighting energy; lighting design method would vary to fit different region; the prediction model of lighting energy consumption is lny=0.479lnx₁+0.248lnx₂-0.217;customers were more sensitive about illumination adequacy than uniformity and increasing the illumination improved subjective evaluation.

Abstract:Meteorological parameters is a major factor affecting building thermal environment and heating and air conditioning energy consumption, and climate change has a significant impact on building energy consumption. Based on 30 years historical observations of Chengdu from 1971 to 2000, the hourly meteorological data file is generated which is required by the building energy simulation software EnergyPlus. The changes of 30-year monthly mean dry bulb temperature, monthly mean solar radiation in the area were compared and analyzed, and the heating, cooling and building total energy consumption is simulated and analyzed. At last the building energy relationship with meteorological parameters by using multiple regression is established, and the accuracy of the relationship is tested. The results shows that: the regularity relationship between change of building energy consumption and meteorological parameters isn't significant. the building monthly total energy consumption and meteorological parameters show a pure quadratic relationship, and a cross binomial relationship between monthly heating energy consumption, monthly cooling energy consumption and meteorological parameters is found. Building monthly energy regression model can predict the relationship between building monthly energy consumption and various meteorological parameters accurately, and the monthly heating energy consumption and monthly cooling energy consumption regression model predicts better than monthly total energy consumption model.

Abstract:Water evaporation in Huizhou traditional dwellings has played a positive role in environment formation. Evaporation model was built by analyzing heat balance of water evaporation. The model was calibrated against evaporation data which were obtained from field measurement in traditional dwellings. The results show that the model could effectively predict the water evaporation process in Huizhou traditional dwellings. In addition, the error of standard deviations and the average relative error between calculate values and experimental values are 41.5 g/(m²·h) and 4.2%, respectively. Correlation analysis results show that the water evaporation is most correlated to the ground temperature, followed by solar radiation, wind speed, relative humidity and air temperature, and the correlation coefficients are 0.909, 0.779, 0.736, -0.654 and 0.622, respectively.

Abstract:Currently, pump & treat, which is one of the common repair contaminated soil methods, could get rid of some pollutants efficiently. However, it's very limit for poor permeability and low concentration pollutions. In consideration of the property that water would shift from unfrozen region to freezing front and soil permeability will also enhance by freeze-thaw action under certain conditions of temperature gradients and moisture, the pump & treats extraction productivity was explored in experimental research throughbasic experiments. Clay mixed with NaCl (simulation of heavy metal pollutants) is used as the study object and experienced the unidirectional freeze-thaw and pollutants cleansing test, The feasibility of freeze-thaw action flush pollutants is explored. The experimental results show that the freezing and thawing action is contribute to advancing pollutant removed efficiency and a reliable experimental basis is provided for the following implementation of the situ soil flushing.

Abstract:The influence of current density, electrolysis time, pH, Cl^- and SO₄^2- concentration on the inhibition of Microcystis aeruginos was investigated by Boron-doped diamond plate electrode. Algal cell morphology before and after electrochemical treatment were observed. The results show that the four factors had significant effects on the inhibition of algal cells. The inhibition of algae increase with the increase of current density and electrolysis time, which are good at 17 mA/cm² because of leading to the rupture of algae cells and outflowing of intracellular substances. Completed inhibition of algae could be obtained after 20 minutes. More than 20 minutes Electrolysis time have no obvious effect on the inhibition of algae. Completed inhibition of algae could be obtained under the initial pH in neutral and acidic conditions. The inhibition of algae increase with the concentration of Cl^- and SO₄^2- in the solution. The concentration of Cl^- of 6 mg/L could completely inhibit the growth of algae cells. The algal solution without chloride ion continue to grow after 4 days.

Abstract:In this study, a cationic polyacrylamide (P(AM-DAC)) was synthesized via the copolymerization of acrylamide (AM) and acryloyloxyethyl trimethyl ammonium chloride (DAC) under the initiation system of ultrasonic with VA-044. In the synthesis, the short preparation time and high preparation efficiency were found. The effects of key factors in the preparation on the intrinsic viscosity of P(AM-DAC) were investigated, and the optimal synthesis condition was obtained. The results indicated that the highest intrinsic viscosity of P(AM-DAC) was reached at the molar ratio of AM to DAC of 3:2, the initiator concentration of 0.02%, and ultrasonic time of 20 min and pH of 4. It was confirmed that P(AM-DAC) was the copolymer of AM and DAC, and the functional groups of -NH₂, C=O, -CH₂-N⁺ and -OH were found in it. P(AM-DAC) possessed the acceptable stability at the temperature range of 30 to 200 ℃.

Abstract:In order to investigate the feasibility of removing the nanoparticles(NPs) from water by coagulation, the effects of inorganic coagulants (PAC, PFS, PAFC) and organic flocculants (CPAM, APAM, NPAM) on the removal efficiency of TiO₂ NPs were evaluated. The effects of dosage, pH, sedimentation time, hydraulic conditions and compound flocculants were also investigated. The highest removal rates of PAC, PFS and PAFC were 92.51%, 84.43% and 95.66% while the removal rates of CPAM, APAM and NPAM were only 61.72%, 29.06% and 55.37% respectively. The optimum coagulation dosage were 40 mg/L PAC and 3 mg/L CPAM, while the pH was 9, G value was 143.5/s and the sedimentation time was 15min,and the corresponding removal efficiency of TiO₂ NPs was 99.6%.

Abstract:With the flocculation test carried out on the pickled cabbage water, the type of flocculant and coagulant, molecular mass of PAM, sequence of addition, pH, temperature, and stirring speed are investigated on the effect of flocculation treatment of pickle waste water, which makes the next stages of biochemical treatment more easily and provides a reference for the selection of the flocculation parameters of kimchi factory. In the pickled cabbage wastewater which contains a large number of NaCl, the flocculation and sedimentation performance are improved by the addition of PAM because of its bridging functions. Under the condition of PAC dosage of 150 mg/L, PAM dosage of 25 mg/L, pH6, at the temperature of 30 ℃, by 2 minutes of a magnetic stirrer stirring (250 rpm/min) and a slow stirring (90 rpm/min), static 30min, the best result is obtained. The removal rate of COD and turbidity reaches 37.7%, 96.7%.

Abstract:The chaotic local-region forecasting model is suitable for nonlinear and non-stationary urban daily water supply forecast, and the neighbourhood selection has a direct impact on the model prediction accuracy. The traditional method usually takes the embedded dimension m as a reference, and selects m+1 nearest neighbours by experience. It usually introduces the pseudo nearest neighbours, which leads to the reduction of the prediction accuracy. Accordingly, the evolutionary tracing method is introduced into the prediction of urban daily water supply. By mining the historical evolution of nearest neighbours, the reference samples are optimized to improve the prediction accuracy. The proposed method is validated by the actual daily water supply data. The results show that the optimal approach is significantly improved by using evolutionary tracing method, and the average absolute error is reduced from 2.501% to 1.683%.

Abstract:Based on the modified Johnson-Cook material model, ANSYS /LS-DYNA was used to establish the model of K8 single-layer spherical reticulated shell, and the structural explosion responses were calculated and analyzed with different space heights. Firstly, the propagation law of the shock waves inside the structure was analyzed,and the feasibility of parameters selection was verified. Secondly, the dynamic responses of the spherical reticulated shell under the internal explosion were discussed, and the influence of different constitutive models on the explosion responses was comparative analyzed. Finally, the ratio of the volume enclosed by lower supporting structure to the total volume surrounded by the whole structure was defined as a space height coefficient. The influence of the space height coefficient on the dynamic responses of spherical latticed shell (with or without holes on wall) was studied and discussed. The results show that the shock waves have a converging effect at the corner of the spherical shell structure, combined with the reflected shock waves, which may seriously affect the dynamic responses of the spherical shell. For the spherical shell with wall no openings, the explosion responses were greatly affected by the reflected shock wave, and for the spherical shell with wall openings, the explosion responses were greatly affected by the space height coefficient. Based on the research results, the reasonable space height coefficient of explosion-resistant design on spherical shell structure under internal explosion was proposed.

Abstract:According to the fatigue damage characteristics of galvanized wire, the propagation process is decomposed into 7 stages, including galvanized layer failure, matrix corrosion pit initiation, short crack propagation, long crack propagation and fracture damage stage. Then the expression of time in different stages and the galvanized wire fatigue life expression is established, and the evaluation method of corrosion fatigue is putted forward based on fracture mechanics. Finally through the case analysis of complex factors such as operation under the condition of corrosion environment and stress amplitude, the impact on the wire corrosion fatigue life is analyzed. The results show that the corrosion fatigue life of wire is mainly composed of steel galvanizing layer corrosion, pit development and short crack extension, and in order to accurately assess the corrosion fatigue life of wire, the operating environment and traffic load need to be grasped.

Abstract:This paper examined the effects of crucial parameters, including W/B, binder content, alkali component, on compressive strength of alkali-activated slag concrete. Based on results obtained, the statistical distribution and variance (standard deviation) of compressive strength results were estimated, and the analysis results from experimental data indicated that the compressive strengths of AASC at the age of 28 day fitted normal distribution and is inversely proportional to the liquid-solid ratio. The relationship between W/B and compressive strength was established through regression analysis, the regression coefficient of formula α_a and α_b is 0.796 and 0.897 respectively. As such, a simple mix design method for alkali-activated slag concrete was proposed.

Abstract:The influence of prepared silicate on properties of traditional sticky rice-lime mortar and their scientific mechanism are discussed by means of SEM, XRD, and FTIR. Results indicate that silicate are effective to increase the hardness, compressive strength, freezing-thaw resistance and water resistance of sticky rice-lime mortar significantly. The sticky rice-lime mortar with prepared silicate, overall properties of the prepared silicate-sticky rice-lime mortar are very good. Compared with pure sticky rice-lime mortar, the 66 d compressive strength of prepared silicate-sticky rice-lime mortar is 1.45 MPa, and the freeze-thaw resistance and water resistance increase by 133.3% and 43.8% respectively. Formation of tobermorite is possible to account for the good mechanical property of sticky rice-lime mortar with silicate.

Abstract:The causes of low temperature diseases of cement asphalt emulsified mortar (CA mortar) was analyzed. The influences of hardening process and filling quality of sulfur aluminum cement(SAC) and polymer latex on CA mortar in winter were studied, and the results showed that CA mortar is super retarding in low temperature, and the system stability deteriorated, then some diseases appeared such as bleeding, peeling by removing slab, et al. The SAC could accelerate the hardening process with the substitution amount of SAC increases, and the setting time of CA mortar is faster. With the increase of temperature, the stirrable time of latex-cement system showed a decreasing trend, and uniform and stable of fresh CA mortar could be improved by latex with suitable thickening performance in low temperature. The expansion rate and 24h compressive strength of CA mortar which combined admixture SAC(the content of 10%) and polymer latex(the content of 8%) met the standard requirements, in 0.5 ℃~7.7 ℃ environment, and CA mortar showed cross-section uniformity and smooth surface without peeling by removing track slab, which meet the requirement of the technology requirements.