Thermal performance investigation of heat storage soil wall for early spring cultivating seedlings in solar greenhouse in severe cold area

This study investigated indoor radon concentrations in modern residential buildings in the Cold Area and Severe Cold Area in China. A total of 19 cities covering 16 provinces were selected with 1,610 dwellings measured for indoor radon concentration. The arithmetic mean and geometric mean of indoor radon concentration were 68 Bq m -3 and 57 Bq m -3 , respectively. It was found that indoor radon concentrations were much higher in the Severe Cold Area than those in the Cold Area. The indoor radon concentrations showed an increasing trend for newly constructed buildings. It was estimated that the average effective dose from inhalation of indoor radon is 2.15 mSv and 1.60 mSv for the Severe Cold Area and Cold Area, respectively. The more and more rigid energy-saving design for residential buildings in the Severe Cold Area and Cold Area has an obvious impact on the increased trend of indoor radon due to extremely low air exchange rate in China.

In order to improve the overall structural stability and thermal insulation capacity of existing buildings in severe cold areas, green energy-saving ecological transformation methods of existing buildings in severe cold areas are proposed. The concrete stress analysis method of the joints in the frame is used to calculate the bearing capacity and prestress of the beam-column joints. Based on the method of parameter analysis, the calculation model of shear capacity is established. The embedded anchoring method is adopted to realize the equal strength connection of beam-column joints. Increase the unbalanced moment between reinforcement and steel plate, and improve the stability and reliability of beam-column joint fixation. The overall structural optimization method of joint shear performance is adopted to reduce the distance between lap reinforcement and steel plate, so as to realize the green energy-saving ecological transformation design of existing urban buildings in severe cold areas. The test results show that the service stress and tensile resistance of the reconstructed existing building area are higher than 60, the tensile capacity is good, and the slip of the lap reinforcement is effectively controlled. At the same time, this method improves the stability of beam-column elements and the overall thermal insulation performance of existing buildings in cities in severe cold areas. The next research will focus on the transformation of other structures.

Investigation on Energy Consumption in Rural Residential Buildings During Heating Season in Severe Cold Areas in Northeast of China

With the rapid development of the global economy, the world energy consumption is increasing day by day. Mankind is facing the problem of energy shortage. Energy conservation and emission reduction has become the focus of countries all over the world. In order to study the influence of building envelope on building energy efficiency in severe cold area, the sensitivity analysis is used to analyze the influence relationship between building envelope and building energy efficiency. Combined with DeST simulation software, the building model is established, and the arc mean elasticity method is used to analyze the sensitivity of building energy load to different building envelope parameters. The results show that the external windows of the building envelope have the greatest impact on the building energy efficiency, followed by the external walls, and the roof has the least impact on the energy efficiency. The sensitivity coefficients of the annual cumulative load to the external windows, exterior walls and roofs of buildings are 7.93%, 5.76% and 5.75% respectively. Studying the influence of enclosure structure on building energy efficiency in severe cold areas has important practical value for reducing building energy consumption in severe cold areas, and provides data reference for scientifically improving building energy efficiency and building skill transformation in severe cold areas.

In existing prefabricated substations, the exterior wall is of prefabricated building enclosure structure. In this paper, the thermal insulation performance is optimized and the optimized wallboard is experimentally studied by guarded hot box method. The study shows that metal-faced rock wool sandwich panel with optimized thermal insulation performance can fully meet the requirements of prefabricated substations for the thermal insulation performance of enclosure structures in severe cold areas, which provides an experimental basis for promoting the construction of prefabricated substations in severe cold areas, which has important application value in engineering and social benefits.

With a vast territory and seven climate zones, China’s urbanization is constantly improving while building energy conservation and emission reduction are facing severe challenges, especially in severe cold areas. In China’s Liaoning Province, urban public buildings and rural residential buildings consume huge amounts of energy. According to the characteristics of Liaoning, “passive technology advanced, active technology second” is the best choice for energy saving and emission reduction. Taking Sino-German Energy Conservation Demonstration Center in Shenyang Jianzhu University as an example in this paper, through analysis of the operation monitoring data of energy consumption, the objective is to provide a good reference method and a design strategy for the near zero energy buildings in the severe cold areas and to verify its feasibility. At the same time, the parametric design technique is applied to feature-based design system, such as multi objective optimization and genetic algorithm combined simulation technology, Rhino Grasshopper Energy plus energy saving technology and cost-benefit analysis model to obtain the optimal solution. It provides innovative technology demonstration for building energy conservation in the severe cold areas.

The negative impact of indoor formaldehyde pollution has become a growing interest, especially in severe cold areas, since most residential buildings do not have enough ventilation and people are unwilling to open windows. In order to explore the status and the influencing factors of indoor formaldehyde pollution in severe cold areas and predict the formaldehyde concentrations in these areas, a study of 60 residential buildings in Liaoning, China, was carried out using the method of phenol reagent spectrophotometry. While testing the formaldehyde concentration, the infiltration air change rate of the room was also tested using CO2 as a tracer gas. The correlation between formaldehyde concentration and its influencing factors was analyzed by SPSS software. Multiple linear regression equations were established for the linear regression analysis. The measured data were used to assess the formaldehyde cancer risk of residents in Liaoning. The test results showed that the most serious rates of average formaldehyde pollution occurred in summer with a concentration of 0.097 mg/m3, and the bedroom was the room most seriously polluted by formaldehyde in autumn with a concentration of 0.104 mg/m3. According to the correlation analysis, the formaldehyde concentration was significantly correlated with the indoor temperature, years of decoration, and the infiltration ventilation rate. The linear regression equation for predicting the formaldehyde concentration was established. According to the risk assessment of the test results, residents in Liaoning are already at risk of cancer caused by formaldehyde.

Research on outdoor thermal comfort of high-density urban center in severe cold area

Energy-saving retrofits of prefabricated house roof in severe cold area

Objectives: This study aims to investigate and discuss on the effects of Tai Chi exercise on knee flexibility, lower limb muscle control, fall risk prevention and self-efficacy for elderly males living in severe cold areas .Methods: In the experiments, 36 healthy elderly males, who were aged between 65 to 70 and from Kuancheng District, Changchun City, Jilin Province, Northeast China, were selected and randomly divided into experimental group and control group:during the eight-week experiment, subjects in the experimental group exercised Tai Chi, with 4 times a week, and duration of 45 minutes for one section. The researcher evaluated subjects’ knee flexibility, lower limb muscle control, fall risk prevention, and self-efficacy before and after 8 weeks of Tai Chi exercise intervention. Also, Five Times Sit to Stand Test, 6-min Walk Test and Romberg’s Test were launched for the subjects. In addition, to assess self-efficacy of all subjects, the researcher adopted General Self-efficacy Scale (GSES) and Time-based Performance Efficacy Scale.Results: Through experimental data analysis achieved by Two-way Repeated-measures ANOVA and Matched Samples T-test, it was figured that thanks to 8-week exercise intervention, subjects in Tai Chi group got significantly enhanced in terms of knee flexibility, muscles of lower limb control and dynamic balance, with strengthened GSES scores.Conclusion: The 8-week Tai Chi exercise possessed functions of effectively improving the knee joint flexibility and lower limb muscle control of the elderly males in severe cold areas, strengthening their self-efficacy, as well as preventing and controlling the fall risks.

Weight of energy consumption parameters of rural residences in severe cold area

Active urban residential public space helps human body maintain normal immune level. Based on some qualitative research and in situ measurement methods, this paper 1) Analysis cold climate’s negative effects on people’s immune level; 2) Develop some empirical research through field survey on climate measurement and structured interview; 3) Advance some planning strategies on urban residential public space based on immune level improvement. The research results can optimize the relevant planning indicators and design principles, promote the formation of a positive urban residential public space in severe cold area, and provide empirical basis for the urban material space planning from the perspective of immune level improvement in severe cold area.

In recent years, the tightness of residential buildings has been continuously enhanced, causing the problem of indoor air quality degradation. Therefore, it is necessary to introduce fresh air that meets the air quality requirements from the outside, and the outdoor air temperature in the severe cold area is low, which increases the fresh air load of the building. To save energy consumption, regularly use air heat recovery equipment to recover heat energy. In order to verify the energy-saving effect of the fresh air heat recovery system in residential buildings in severe cold areas, taking an experimental building in Shenyang as an example, the operating performance curve of an air source heat pump equipped with a fresh air heat recovery system was measured, and TRANSYS software was used to simulate and compare two kinds of heat recovery mode, namely the exhaust mixture of outdoor air and pure out door air low temperature heat source. The results show that when the exhaust air is mixed with outdoor air as the low-temperature side heat source, the average COP value reaches 3.24 and increases by 17%, which can save 7.6% of the energy consumption of the air source heat pump throughout the entire heating season.

With the general improvement of people’s living standard, residents in severe cold areas have further increased their requirements for residential insulation, which provides new issues for the energy-saving design of thermal insulation of their residential buildings. This paper mainly introduces the energy-saving design of the thermal insulation structure of residential buildings in severe cold areas such as exterior walls and roofs, including the selection of their specific materials. It is hoped that the insulation performance can be higher and the energy-saving effect can be better.

Investigation of outdoor thermal sensation and comfort evaluation methods in severe cold area