Buildings In Cold Areas Research Articles

A Quasi-Steady Model for Estimating the Rate of Frost Heave When Subjected to Overburden Pressure

The soil beneath buildings constructed in cold regions is affected by frost heave, causing the walls to crack and even the buildings to incline and collapse. Therefore, predicting the frost heave when subjected to overburden pressure is crucial for engineering buildings in cold areas. Utilizing the conservation equation of mass, Darcy’s equation, and the assumption that the pore water pressure at the top of a frozen fringe, denoted as uw, during the quasi-steady state can be approximately estimated using the Clapeyron equation, a quasi-steady frost heave rate model considering the overburden pressure was proposed. This study considered the difference in pore water pressure within the frozen fringe, which causes water to move from the unfrozen zone to the ice lens, where it subsequently accumulates and freezes into ice. The pore water pressure at the bottom of the frozen fringe, denoted as uu, can be estimated using the soil water characteristic curve (SWCC). The thickness of the frozen fringe was determined using the freezing temperature, segregation temperature, and temperature gradient. The segregation temperature was determined using the two-point method. Additionally, the model suggested that, when uw = uu, the movement of water stopped, leading to the end of frost heave. To validate the proposed model, three existing frost-heaving experiments were analyzed. The findings demonstrated that the estimated rates of frost heave of the samples closely matched the experimental data. Additionally, external pressure delayed water migration. This study can offer theoretical support for building engineering in cold regions.

Indoor Radon Concentrations in Severe Cold Area and Cold Area and Impact of Energy-saving Design on Indoor Radon in China.

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.

Practical Exploration of Net-Zero Building Technology in Hot Summer and Cold Winter Regions—Qingdao Sino-German Eco-Park Longfor Guangnian Project as an Example

Energy saving and carbon reduction in the building sector is crucial to the realization of China’s “double-carbon” goal, and the development of passive house/net-zero buildings is an important initiative to achieve this goal. This paper takes Longfor Guangnian, a passive house project in Qingdao, as a case study, summarizes the technical practice of net-zero buildings in coastal areas with hot summers and cold winters, and gives an optimization plan in combination with the existing problems of the case. The final result is to improve the building energy efficiency and optimize the building energy structure. It accumulates experience and provides reference for the promotion of net-zero buildings in cold areas, and provides support for green and low-carbon development in the field of housing and urban-rural construction.

Research on Carbon Emission Pre-Assessment of Residential Buildings in Xi’an City during the Scheme Design Stage

The effect of energy saving and carbon reduction in the building industry is closely related to the realization of China’s double carbon goal. In this study, a two-dimensional framework for building life cycle carbon emissions was established, which takes into account the early stages of building design such as the feasibility study stage and scheme design stage. Taking 57 residential buildings in Xi’an City as examples, the life cycle carbon emission characteristics of residential buildings in cold areas were introduced. This study found that the life cycle carbon emission intensity is about 45~55 kgCO2/(m2·a). The operation and maintenance stage and building materials production stage accounted for the largest proportion of carbon emissions, and the sum of carbon emissions of the two stages accounted for 92.3% of the total carbon emissions. In addition, based on the probability density function, the carbon emission intensity distributions of the building life cycle, building material production stage, building material transportation stage, and operation and maintenance stage were analyzed, and it was found that each distribution fitting graph was generally in line with a lognormal distribution, and their expected value provided a reference index for carbon emission pre-assessment in the feasibility study stage. Based on the analysis and determination of 11 independent variables that affect the total carbon emissions, such as area, floor number, story height, and number of households, a multiple linear regression model for carbon emission pre-assessment in the design stage of building schemes is proposed. The R2adj of the model is 0.985 and the error is about 10%. The prediction model can provide beneficial guidance for the life cycle carbon emission prediction in the design stage of building projects, so as to reduce carbon emissions by changing building design.

Scheme Design and Energy-Saving Optimization of Cold and Heat Energy Supply System for Substation Main Control Building in Cold Area

In the context of global climate change, the implementation of building energy conservation and carbon reduction, as well as the realization of zero-energy buildings, is a key measure to cope with climate change and resource depletion. A substation is an indispensable building in the process of urbanization construction. However, in existing cold areas, the heating form of substations generally adopts electric heating, which consumes a large amount of energy. This paper optimizes the existing HVAC form of substations through the rational utilization of surrounding environmental resources and puts forward reasonable building energy-saving and carbon-reduction methods. It demonstrates the feasibility of combining solar photovoltaic power generation systems, air source heat pumps, and natural ventilation to optimize energy savings and carbon reduction in the main control building of a substation in a cold area. The computational fluid dynamics (CFD) method is used to demonstrate the feasibility of natural ventilation during the summer and transition seasons. The data indicate that the installation of a solar photovoltaic power generation system results in an average annual power generation of 18.75 MWh. Additionally, using an air source heat pump can save 44.5% of electricity compared to electric heating. When both a solar photovoltaic power generation system and an air source heat pump are used to provide a building with cold and heat sources, the annual emissions of CO2 can be reduced by 4.90 tons compared to a traditional electric heating system.

Optimization analysis of residential space in cold region based on building performance simulation

Purpose-Rural residential buildings in China?s cold areas still have large room for improvement in lighting, energy saving and other aspects due to their own development lag. Design/methodology/approach-Taking Zhaoyuan County residential buildings as an example, the spatial elements of residential buildings are quantified, and the variation intervals of each spatial element are determined based on this. Then the standard model of residential buildings is constructed, and the changing trend and related mechanism of heating energy consumption and natural lighting under the change of residential space elements are discussed. Findings-The results show that: in terms of heating energy saving, there is an obvious optimal solution between the window wall ratio of the south facade and the orientation of residential buildings; in indoor natural lighting, all spatial elements show positive and negative correlation without considering glare; building depth, eave height and plane girth area ratio are the key variables affecting heating energy consumption. Window to floor ratio, building eave height, building depth, and plane aspect ratio are the key variables that affect indoor lighting. The research results can provide reference for the energy-saving construction of residential buildings in cold areas.

Technical and economic performance study on winter heating system of air source heat pump assisted solar evacuated tube water heater

Winter heating with clean energy is very important for coal substitution in rural areas of China. In Northwestern China, winter weather is usually below zero and winter heating lasts at least 5 months, which is a big expense for rural residents. It is well known that solar energy, air source heat pump and other energy-saving technologies could effectively cut down the expenditure. However, it is difficult to consider the economics and stability of winter heating with free solar energy alone, and the cost of winter heating with heat pump alone is too high for locals to afford. Therefore, the concept of air source heat pump assisted solar energy was proposed and a solar evacuated tube water heater -air source heat pump system was built in Lvhua Village, Lanzhou City. Experiment and simulation studies were carried out to discover the technical and economic performances when the system operates in three modes, namely, heating by solar water heater, air source heat pump and solar water heat pump (heat pump used hot water from solar collector as heat). Simulation results were verified and highly consistent with experimental results on December 20th, 2021. The results show that in whole heating season, air source heat pump assisted solar energy system greatly improves technical and economic performance in comparison with heating by solar water heater and air source heat pump. The average daily collector efficiency in the heating season is 45.5 %, and the average daily effective solar heat collection is 43.6 kWh. During the heating season, the effective solar heat collection is 6587.1 kWh, the electricity consumption is 5229.7 kWh, the heat supply is 16392.2 kWh, the solar fraction is about 40.2 %, the energy efficiency ratio is 3.1, the average COP of solar water heat pump is 3.5, and the average COP of air source heat pump is 3.0. The primary energy saving rate of the system is 66.4 %, the dynamic investment pay-back period is 6.5 years, and the CO2 emission reduction is 10960.7 kg. The results demonstrate the feasibility of the winter heating system of air source heat pump assisted solar evacuated tube water heater, which provides a new way for the heating of rural single buildings in cold areas.

Evaluation of Thermal Insulation Performance of Building Exterior Wall Based on Multiobjective Optimization Algorithm

A complete evaluation of conflicting and nonlinear multiperformance is referred to as an evaluation system. Therefore, multiobjective optimization research for building performance is of great importance. Considering the above problems, this paper proposes a multiobjective performance optimization platform at the architectural design stage. The optimization research is combined with the basic algorithms. It is based on Grasshopper software. It aims to provide a fast and effective method for the optimization design of sustainable buildings. It is important to note that this workflow has no restrictions on what to optimize for or what to target, and can be determined on a case-by-case basis. To evaluate the use of the work platform and make the research results more extensive, the standard model of the inner corridor space building in office buildings in cold areas was extracted. The extracted standard model was taken as the final research object. At the same time, the convergence, distribution, and comprehensive evaluation indexes of the simulation results were analyzed. The quantitative influence parameter system of window parameters on the total building energy consumption, lighting uniformity, and glare probability was established. A series of parametric design models based on the comprehensive optimal solution of building energy consumption and lighting quality was obtained. The main purpose of this paper is to design a green building design method based on the principle of goal-oriented design. This paper, combined with the group search function of nondominated genetic algorithm (NSGA-II), the energy consumption of the building, and the evaluation function of indoor thermal and humid environment, is obtained and linked with MATLAB. The energy consumption of residential buildings and indoor thermal comfort were taken as the optimization objectives of the design scheme. The automatic optimization model of the architectural design scheme was established. Finally, the Pareto solution set of the architectural design scheme is obtained, and the designer can select the appropriate design scheme of the Pareto solution set according to the actual situation of the project, to meet the requirements of green building design. The design scheme optimized by this method can effectively reduce building energy consumption and improve indoor thermal comfort.

Research on Passive Reconstruction and Energy Supply System of Existing Buildings in Cold Areas

Faced with the problems of existing buildings in cold areas, such as poor insulation performance of envelope, high heating cost and substandard indoor temperature in winter, based on DeST-h energy consumption simulation software, taking typical single buildings in Zhangjiakou as an example, several factors affecting building energy consumption were analyzed. The building energy consumption values in heating season under 9 envelope reconstruction conditions were obtained by orthogonal experiments, and 4 different energy supply systems were designed for buildings under 9 envelope reconstruction conditions. The “with or without comparison method” is used to evaluate the building energy efficiency of 40 working conditions after the superposition of the initial state and passive transformation of existing buildings in the whole life cycle. The evaluation results show that the external wall insulation and extrusion plate thickness is 80 mm, the roof insulation and extrusion plate thickness is 100 mm, and the glass type is ordinary hollow glass ( 6 + 9 + 6 ). The air source heat pump assisted energy supply effect is the best, but the overall economy will change with the initial investment, local electricity price policy and building scale.

Design and thermal performance evaluation of a new solar air collector with comprehensive consideration of five factors of phase‐change materials

Solar air collectors are widely used for the heating of buildings in cold areas owing to their high light–heat conversion rate, non-freezing of air medium, and low manufacturing cost. However, the intermittency of solar energy conflicts with the user's comprehensive heating demands, thereby hindering the promotion of solar air collectors. To solve the above issue, in this study, a solar air collector model with a new heat storage device (Type 2) was designed by comprehensively considering five factors, such as phase-change temperature, heat storage capacity, heat transfer efficiency, heat storage time, and heat release time. Thereafter, the ordinary solar air collector model (Type 1) was compared with the Type 2 solar air collector. Comparative analysis of the thermal performance evaluation index revealed that the heat release time of the Type 2 solar air collector was approximately 15 h after sunset, and the heat storage time was only approximately 7.5 h. Compared with Type 1 solar air collectors and previousachievements, the average daily heat collection efficiency of Type 2 solar air collectors decreased by 20.08% and 16.58%. The findings of this study indicate that the Type 2 solar air collector has a good effect in terms of heat storage time, heat release time, and heat peak migration, and is thus conducive to solving the contradiction between the intermittence of solar energy and user's comprehensive heating demands.

Thermal comfort in residential buildings using bimetal radiator heating vs. floor heating terminals

Bimetal radiator heating terminals (BRH) have gradually replaced the traditional cast-iron radiator and have been widely used in urban residential buildings in cold areas of China. Meanwhile, floor heating (FH) terminals are increasing rapidly in recent years. Therefore, two common heating terminals in urban residential buildings exist in cold areas of China, namely, BRH and FH. The comfort of the two heating terminals has been a focus of controversy. To compare the thermal comfort of BRH and FH terminals, field tests and subjective questionnaires were made on the residential buildings during heating seasons in cold areas in China. A total of 71 residences and 136 occupants were investigated in this field study, where 294 and 299 valid data sets were obtained from FH and BRH terminals, respectively. The results showed that FH has significantly higher mean radiant temperature (MRT) and operative temperature, although no significant differences in indoor air temperature, relative humidity and air velocity between the two heating terminals are observed. FH terminals were significantly less dressed compared with those from BRH terminals at the same temperature. The actual lower limit of 80% acceptable temperature for FH and BRH in winter were 15.9 °C and 17.0 °C, respectively. The use of the FH terminals increased people's acceptance of the low-temperature environment and reduced their expectation for high-temperature environment. PMV significantly underestimate the thermal sensation of the occupants. This paper can be a reference for the selection of heating terminals and may lead to more efficient energy use for heating systems.

Wind Energy Collection System Based on Phase Change System and Deformable Materials

The purpose of this paper is to design and discover a new system, which can realize the collection, transformation and storage of energy from wind energy in the environment ^ temperature/physical deformation → material phase change → energy storage, so as to achieve the effect of green energy saving. At the same time, it can provide theoretical support and design basis for the design of high-rise Garden residential suite in cold region. Wind energy is collected through the narrow channel effect. With the help of deformation induced ferrite phase transformation technology and memory alloy materials, the collected energy is stored in the new colloid/graphene battery equipment. With the help of the relevant content research parameters, a systematic digital model is formed, and the basic database is established to simulate the external environment of high-rise Garden residential buildings in cold areas. Through the design of a new wind energy collection system and embedded in the simulation environment, the wind energy utilization in cold, low sunshine, low wind speed or unstable wind speed areas is realized, and the green energy conservation, environmental protection and sustainable development in such areas are realized. Then, the feasibility and effectiveness of the system are demonstrated according to the experimental results, and a systematic theory is formed.

Research on Building Energy Consumption Optimization Based on Improved Particle Swarm Optimization Algorithm

Aiming at the poor efficiency of traditional PSO algorithm in energy consumption optimization of office buildings in cold areas, a building energy consumption optimization method based on improved PSO was proposed. Firstly, the basic principle of PSO algorithm is analyzed, and then the PSO algorithm is improved by GE or AG operators. On the basis of the improvement, different test functions were used to optimize the algorithm, and then the maximum PSO parameters were verified. Finally, the above improvements are applied to a building example. The results show that the improved PSO energy consumption optimization method can not only improve the fast travel performance of the algorithm, but also reduce the overall search time.

Research on envelope design of ultra low energy consumption passive building in severe cold area

At present, the common solid clay brick structure is widely used in residential building walls, which leads to higher indoor humidity, serious energy loss, waste of economy, environmental pollution and lower people’s comfort. The passive technology of ultra-low energy consumption can improve the insulation performance of the enclosure, reduce the energy consumption of heating and improve the comfort of the owner, and finally achieve the goal of energy saving of low energy consumption buildings in the cold area.

Application and analysis of low temperature air source heat pump heating system in Cold Area

A low temperature air source heat pump (ASHP) heating system of residential building in cold area was designed and tested. The operating characteristics of the low temperature ASHP heating system in the typical day, typical month and the whole heating season were analyzed. The system energy saving performance in the whole heating season was also calculated. The results showed that the low temperature ASHP system operated stably in cold area and has energy-saving effect.

Experimental study on freeze-thaw performance and thermal conductivity of green ecological concrete

For the existing and new buildings in cold areas, this paper makes full use of the agricultural waste of finely ground rice husk and the recycled coarse aggregate of the concrete of the construction industry waste to form green ecological concrete by compounding, which can promote the ecological environment and the secondary recycling of agricultural and industrial waste; compounding finely ground rice husk and recycled coarse aggregate can save cost, improve the later strength of concrete, and green energy saving and heat preservation, and protect Ecological resources and environment. After mixing the two to replace cement and natural coarse bone by the same amount, we prepared two sets of concrete thermal conductivity test blocks, four sets of frozen and thawed test blocks, and tested the thermal conductivity of concrete, mass loss rate. The test results showed that the thermal conductivity value of the green concrete was 1.17 W/(m-K), and the mass loss rate was 3.85% and 4.08% after 25 and 50 freeze-thaw cycles respectively, and the green ecological concrete had excellent energy saving and durability.

Analysis on Influencing Factors of Energy Consumption of Public Buildings in Cold Areas

DeST-c software was used to build the building model, and the single factor experiment method was used to carry out the simulation study. Under the condition that only single factor was changed and other influencing factors were unchanged, the influence law of each energy influencing factor on energy consumption was analyzed, and the influencing factors were Analysis of the impact degree on energy consumption, the results are as follows: body shape coefficient > outer window heat transfer coefficient > outer wall heat transfer coefficient > south window ratio > roof heat transfer coefficient > north window and wall ratio, namely, body shape coefficient, outer window transmission. The thermal coefficient and the external wall heat transfer coefficient are the main influencing factors of building energy consumption.

Optimization and cost analysis of thickness of vacuum insulation panel for structural insulating panel buildings in cold climates

Structural insulation panels (SIPs) are considered promising building products that achieve the low-energy goal, and its potential energy performance can be further improved by combining it with a vacuum insulation panel (VIP) in cold climates. The aim of this study is to determine the optimal SIP with VIP (VIP–SIP) thickness and to minimize the energy cost. We conduct a VIP-SIP thickness optimization and cost analysis for five cold sub-regions using P1-P2 methods. First, we develop an energy model using the building energy simulation software OpenStudio considering the VIP aging effect, and the accuracy of this model is validated using field test data. Results indicate that as climates become colder from Cold area B to Severe Cold area A, the optimal VIP thickness increases from 3.5 mm to 31 mm, whereas the optimal PU thickness decreases from 66.875 mm to 174.2 mm. In addition, the total cost saving rate increases from 40.5% to 47.9%, and the discounted payback period decreases from 12.59 years to 8.98 years, indicating improved economic feasibility. Furthermore, the influence of the P1 value and VIP price on the optimal thickness and total cost are also discussed. The findings of this study confirm the economic feasibility of combining SIP with VIP in cold areas, and provide feasible parameters for the design of low-energy buildings in cold areas of China.

Research on Evaluation System of Green Residential Buildings in Cold Areas of Sichuan

With regard to the rapid growth of China’s building area and the increasing energy consumption of buildings, green buildings have become an important issue for balancing economic development and environmental impact. However, the current evaluation systems for various types of green buildings are often unable to achieve a set of standards in practice due to the distinct regional characteristics of each region. Therefore, in view of the regional characteristics of the climate, terrain, ecology, and economic development in the cold regions of Sichuan, it is important to study the evaluation system of green residential buildings suitable for the cold regions of Sichuan. This article focuses on the regional characteristics of climate, topography, ecology, and economic development in the cold regions of Sichuan, and discusses the limitations of the current standards on the practice of green building in cold regions of Sichuan through a sociological questionnaire survey on the comfort of living in the local population. Then from the two dimensions of the advantages of traditional houses and the particularity of national culture, the strategies for the optimization and improvement of the evaluation index system for green residential buildings in the cold regions of Sichuan were proposed. After comprehensively considering the factors that affect the green residential buildings, including the regional characteristics of the cold regions of Sichuan, and the green performance of buildings, local characteristics and ethnic features were included in the evaluation system. The evaluation index system of green residential buildings in the cold regions of Sichuan, consists of 92 three-level indicators. A professional hierarchical analysis software yaahp was used to establish a multi-level hierarchical model between the indicators, and the indicators were compared with each other layer by layer to clarify the importance of the indicators. Based on this, a judgment matrix for each layer was constructed and obtained. The weight of each indicator is accurate, and the scoring mechanism and grading standards are constructed according to it. Through the calculation, the consistency test of the entire model was passed, thereby confirming the scientificity and rationality of the entire evaluation system.

An exploration aboutthe Solar Energy Utilization and the Enclosure SystemRenovation for Rural Residential Buildings in Cold Areas of Northern China——Taking the rural residential renovation design in Zhujialin Village, Linyi as an example

Rural areas in the cold regions of northern China generally suffer from excessive energy consumption, poor thermal comfort, and low thermal efficiency of heating equipment. In order to improve the comfort of ruralresidential buildings, renovation design has become an indispensable part of the current beautiful rural construction.This paper comprehensively analyzes the current situation of rural residential buildings in cold regionsbytaking the transformation ofa farmhouse in Zhujialin of Linyi City as an example. Moreover, the methods of energy-saving renovation of rural houses are explored from two aspects of solar energy utilization and enclosing system renovation. The research provides a feasible reference for energy-saving renovation of other rural areas in the cold regions of northern China.