Enclosure Structure Research Articles

Research on heat transfer mechanism and performance of a novel adaptive enclosure structure based on micro-channel heat pipe

In this paper, a novel adaptive enclosure structure (AES) combining the building wall and heat pipe is proposed for building wall energy saving. The theoretical heat transfer process of the structure is analyzed, and its heat transfer performance is obtained. The theoretical thermal resistance of the structure is about 0.165 K/W. The one-dimensional steady-state heat transfer experiment has been carried out. Under the temperature difference of 35 °C, the surface temperature of the AES is much higher than that of the traditional wall on the heating demand side (about 9.5 °C). The heat transfer experiment under the influence of multiple factors has been carried out. Under heating demand, the indoor side surface temperature of the AES is higher than that of the traditional wall (about 1.5 °C). Under cooling demand, the indoor side surface temperature of the structure is lower than that of the traditional wall (about 0.8 °C). In addition, it is realizable to switch the performance of the AES between efficient heat transfer or good thermal insulation according to requirements. The proposed structure has great potential for reducing the indoor energy consumption and improving thermal comfort, and could provide a new solution for passive energy-saving technology based on building envelope.

Multi-Skin Adaptive Ventilated Facade: A Review

Multi-skin ventilated facades with integrated building elements that respond to climatic conditions (mechanized openings and automatic shading with intelligent control) present the potential of improving overall annual energy savings by adapting the thermal properties of buildings. This paper presents a literature review on multi-skin adaptive ventilated facades. Additionally, this article presents a literature review on building envelopes that contain inner-air layers. The operation modes of the air layer used in building enclosure structures are classified and summarized and the thermal performance and benefits of climate-adaptive facades are discussed and reviewed. The existing operation modes of the air layer used in building envelopes are summarized, outlined and roughly classified into the following types: the enclosed type, the naturally ventilated type and the mechanically ventilated type. One of the sustainable development trends is the investigation and application of energy-efficient climate-adaptive facades. In this study, the energy modeling of a high-rise office building was calculated using the Green Building Studio. The annual energy, the annual CO2 emissions, and life cycle energy for the following three types of facade were estimated: a single-layer facade made of three-layer glass with argon, a double ventilated facade, and a triple ventilated facade with a double chamber. The calculation results show that the annual energy of the building with an adaptive triple-skin facade could be reduced by 15% compared with buildings with a single skin facade.

Shaking table test of the effect of an enclosure structure on the seismic performance of a prefabricated subway station

The enclosure structure is an indispensable part of the construction system of the prefabricated subway station structure (PSSS), and has a significant impact on the overall mechanics and deformation performance, soil-structure interaction, seismic performance and damage characteristics of the PSSS. In order to study the effect of the enclosure structure on the seismic response of the PSSS, a series of large-scale shaking table tests of a PSSS with and without an enclosure structure were carried out to study in detail the seismic response characteristics of the model system, such as macroscopic phenomena, acceleration, strain, and joint deformation. Then the mechanism of the enclosure structure in strengthening the seismic performance of the PSSS was revealed. Finally, the seismic damage evolution mechanism of the PSSS with the enclosure structure was explained systematically. The results showed that the PSSS with the enclosure structure had good seismic performance, and the collaborative seismic design of the enclosure structure and PSSS should be paid attention to. The acceleration response of the foundation soil and PSSS increased due to the existence of the enclosure structure, but the enclosure structure effectively improved the deformation resistance and joint stiffness of the PSSS and reduced the local stress concentration of the structure. The enclosure structure and the prefabricated structure together constituted a complete structural system to resist earthquake action, and could effectively reduce the seismic damage to the PSSS. Under an extreme earthquake, the PSSS degenerated into a three-hinged arch structure, and still had a certain self-balancing performance, which made it less prone to serious damage such as overall collapse. The research conclusions could provide a scientific reference for the design and construction of PSSS.

Study on the Law of Influence of Seepage Field Anomalies on Displacement Field Induced by Leakage of Enclosure Structure

The leakage of an enclosure structure will cause abnormal changes in the seepage flow field, which in turn can lead to the deformation of the enclosure structure and affect the surrounding geotechnical body. In this paper, a fiber-optic temperature measurement system is used to detect the location of the seepage points in a station of the Qingdao subway during open pit excavation, and the abnormal variation of the seepage field caused by the seepage points is obtained by numerical calculation and field measurement. Then, numerical simulation is performed to analyze the effects of seepage field anomalies on the deformation of the enclosure structure and surface settlement. It is found that the seepage flow caused by the leakage point has a significant influence on the surface settlement and the deformation of the enclosure structure. With the increase of excavation depth, the deformation of the enclosure structure increases and the maximum deformation position shifts downward. The deformation of the enclosure structure decreases when the leakage point exists. The surface volume also increases gradually with the excavation, and the maximum surface settlement position shifts outward significantly. The settlement range becomes larger when the leakage point exists.

Analysis on the Influence of Building Envelope on Building Energy Efficiency in Severe Cold Area

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.

Numerical simulation of dynamic response and failure of large-diameter thin-walled cylinder under vibratory penetration

Large-diameter thin-walled steel cylinders, which were first used in the Hong Kong-Zhuhai-Macao Bridge project as an enclosure structure for artificial islands, have been applied in many large-scale offshore projects. The thin-walled steel cylinder may fail during vibratory penetration in certain conditions such as asynchronicity of hammers and presence of corestones or sloping rockhead, which cannot be accommodated in routine wave equation analysis. This study aims to further develop the novel thin-walled offshore retaining structure. A three-dimensional (3D) finite element model is established to simulate the penetration of large-diameter thin-walled steel cylinders using a group of vibratory hammers. The dynamic response of the steel cylinder under multi-point vibrations is sensitive to penetration depth, vibration amplitude, and frequency. Failure under unsynchronized vibrations occurs first at the free part of the cylinder above the ground level. A “shearing” failure mode can develop when the asynchronous hammers cluster together and a “shearing-compressive” failure mode can develop when the asynchronous hammers are alternately distributed. Failure of the cylinder in the presence of geological obstacles occurs at the cylinder toe. “Compressive buckling” and “extrusion buckling” failure modes can develop when the steel cylinder encounters a corestone and sloping rockhead, respectively.

Energy saving simulation of phase change materials in the enclosure structure of archives warehouse in Lhasa

The archives warehouse is an important place to save archives. In order to ensure the safety of archives, the requirements of temperature control are relatively strict in warehouse. Phase Change Material(PCM) is a kind of green environmental protection material, which has the characteristics of phase change latent heat, its energy-saving effect is closely related to outdoor climate conditions. The annual solar irradiance in Lhasa is high, which is conducive to the latent heat effect of PCM. The application of PCM to the enclosure structure of archives warehouse can play the role of thermal insulation in summer and winter. Adding PCM with phase change temperature of 8 °C outside the outer enclosure structure can slow down the temperature fluctuation of the inner wall of the warehouse by 1.66 °C and reduce the energy consumption of the warehouse by 26.05%, the energy-saving effect of archives warehouse is achieved.

Deformation Characteristics of Soil Layers and Diaphragm Walls during Deep Foundation Pit Excavation: Simulation Verification and Parameter Analysis

The research on the deformation of soil mass and ground connection walls is not sufficiently thorough due to the huge risk of deep excavation in soft soil areas. In this paper, finite element software is used to numerically simulate a symmetrical foundation pit in Suzhou, and the reliability is verified by on-site measured data. The purpose of this study is to investigate the deformation mechanism of the enclosure structure and surrounding soil during the excavation of soft soil foundation pits, and to carry out sensitivity analysis. The results show that the maximum subsidence of the surface is 21.25 mm, the maximum horizontal displacement of the underground diaphragm wall is 9.45 mm, and the maximum uplift of the pit bottom is 21.46 mm. By changing the soil layer properties (the elastic modulus, cohesion, and internal friction angle) and the insertion ratio of the diaphragm wall, the maximum horizontal displacement of the diaphragm wall is more easily affected than the maximum settlement of the surface. Based on different research results, the maximum land subsidence and maximum horizontal displacement of the support structure are 0.313–0.060% and 0.070–0.250% of the maximum excavation depth, respectively. Finally, the simulation may have some applicability to other foundation pit excavations.

Research on Deformation Law of Deep Foundation Pit of Station in Core Region of Saturated Soft Loess Based on Monitoring

Saturated soft loess has a large pore structure, high compressibility, low strength, fluid plastic state, and poor engineering properties. It is still one of the key problems that engineering needs to solve. In order to study the influence of deep foundation pit excavation in the saturated soft loess area on the deformation of foundation pits, the deformation laws of ground settlement, enclosure structure, and supporting axial force were clarified based on the field tests on the deformation characteristics of deep foundation pits in areas with the high‐water level in saturated soft loess, combined with geological conditions and on‐site construction procedures. The results indicate the following: water supply and construction process were found to be the main factor in changing the surface settlement curve of deep foundation pits in saturated soft loess; increasing the construction speed of the pit bottom floor, inverted braces, floor frame beams, and sidewall frame beams to close the structure, which is conducive to restraining the deformation of the continuous underground wall and foundation pits in similar areas. In the initial stage of support layout, the axial force of steel support tends to increase too fast or even exceed the standard control value. Therefore, a reasonable preadding axial force is an effective means to control the deformation of the continuous underground wall and the axial force of the steel support. The current research results may provide a reference for constructing deep foundation pits in similar areas.

Analysis of dehumidification method and discussion on improvement measures in solar greenhouse

The solar greenhouse is a passive agricultural facility building which can realize the anti-seasonal production. The main enclosure structure of solar greenhouse is composed of thermal insulation wall, thermal insulation roof and daylighting shed film. The transmittance of sunlight is an important index affecting the healthy growth of plants in solar greenhouse. After testing, the difference between the solar radiation intensity received through the greenhouse film and the outdoor solar radiation intensity during a day has large fluctuations. The reason for this phenomenon is that the humidity in the greenhouse is large, and there is condensation on the greenhouse film, which seriously affects the transmittance of sunlight. The dehumidification methods commonly used in solar greenhouses are summarized, and their advantages and disadvantages are analyzed in this paper. In addition, the problems existing in the current dehumidification methods are discussed. In view of the characteristics of the solar greenhouse that the high temperature needs ventilation and cooling during the day and the low temperature at night needs to supplement heat, a composite ventilation system with anti-condensation, heat storage, cooling and dehumidification is proposed, and its performance is analyzed.

Evaluation of the thermotechnical condition of enclosure structures of cold chambers

Evaluation of the thermotechnical condition of enclosure structures of cold chambers

Thermal insulation performance analysis of high rise building envelope based on finite element analysis

The current analysis method of thermal insulation performance of building envelope neglects the optimization of temperature control parameters, which leads to poor thermal insulation performance, low thermal insulation rate and weak convincing results. Therefore, a finite element analysis method for the thermal insulation performance of high rise building envelope is proposed. Compton backscattering technique is introduced to analyze the influence of the scattering intensity and the ratio of window width on the heat transfer coefficient of the enclosure. Based on the objective function, the thermal performance parameters of retaining wall are calculated and fused. An adaptive iterative optimization method is used to control the thermal performance of the enclosure using the thermal performance parameters of the enclosure. Through the Compton backscatter detection technology, the decision variables of energy consumption of the thermal insulation materials are obtained, and the temperature control parameters of the walls are optimized. The finite element model of enclosure structure is established by using finite element software. The results of finite element model experiments show that the proposed method has ideal heat preservation rate and energy consumption. Compared with the traditional method, the proposed method can keep the preset temperature.

Energy Saving Design of Exterior Envelope of Prefabricated Buildings in Alpine Area

In this paper, the exterior envelope of prefabricated buildings in alpine areas is studied. This paper compares the wind resistance of the fabricated structure composed of two different connection modes, connectors with different thickness, lightweight ceramsite concrete peripheral wall panel and wood composite peripheral wall panel. The test results show that the wind resistance of the fabricated structure composed of wood wallboard mainly depends on the thickness of wallboard, connection mode and connector thickness. Whether sand packing is filled or not has no effect on the improvement of wind resistance of this prefabricated enclosure structure. For meeting the wind resistance of the fabricated enclosure used in the support room, it is recommended to use thick wooden wallboard and connect up and down. The wind resistance of the fabricated enclosure composed of wood wallboard mainly depends on the strength of the wood wallboard itself. The use of wood wallboards with higher thickness can improve the wind resistance of this fabricated structure.

Обоснование конструкции наружных стен из легких стальных тонкостенных конструкций исходя из обеспечения тепловой защиты зданий

Introduction. The article describes features of the design of external steel walls that ensure thermal insulation of buildings. Facade finishing methods are studied. Energy consumption by households, that consumes up to 40 % of all national energy resources, has triggered the development of energy-saving technologies. Their use will solve several problems at once, including conservation of natural energy resources, changing the system of housing and utility services, reducing environmental pollution, increasing the profitability of enterprises and the implementation of energy-saving programmes. Materials and methods. Not only new materials have been developed, but also the whole systems of enclosure structures, which require the study of structural and technological characteristics of facade systems. National standards have not yet been developed for numerous modern, relatively new materials designated for the insulation of external walls. There are two principal methods of wall insulation. The first one is the so-called “wet” method, that entails the use of gypsum mortar. The second one is “dry”; it entails the use of structural hinges to make an air gap between the outer screen and insulation. Results. Russian houses feature very low energy efficiency, and since the cost of electricity and gas for a Russian consumer is lowest in Europe, heat consumption (heating, hot water) is much higher than in Europe. Modern facade systems not only allow to change and beautify the appearance of the city due to a variety of styles and colours of its urban structures, they also improve thermal insulation properties and reduce construction time. Conclusions. External walls, having ventilated facades, are applied in residential and public buildings. They have a supplementary layer of thermal insulation, which is normally used in the construction of these facades. A light steel thin construction is used to make external walls and partitions, in addition to strength they improve the sound insulation of premises.

Обоснование возможности строительства пассивных многоэтажных жилых зданий в климатических условиях Центральной России

Introduction. We won’t be able to solve global ecological problems without solving the energy issue. It is necessary to expand the energy sector and switch to energy saving technologies. Power generation is among sources of negative impacts on the environment and man. The emission of carbon dioxide into the atmosphere, discharge of polluted liquid waste into rivers, creation of huge water reservoirs, warming of water bodies, depletion of fuel resources, deforestation, emission of toxic substances into the atmosphere and water, burial of radioactive waste — this list of negative impacts, produced by the energy sector on the environment, is not exhaustive. At the end of the 20th century, humanity finally rea­lized how serious the problem of carbon dioxide in the atmosphere was. The consolidation of these two issues, namely, environmental protection and conservation of natural resources, tightened the requirements for the construction of buil­dings in terms of thermal insulation, reduction of energy consumption for heating, and introduction of a closed power cycle at production facilities. The article deals with construction of passive multi-storey houses in different climatic conditions of the Russian Federation. The problem of energy saving and thermal insulation of buildings in construction is addressed. The analysis of energy consumption by passive buildings in the climatic conditions of Central Russia is made. Materials and methods. Currently, heating consumption by all types of buildings during the heating season in Russia is analyzed in accordance with Annex G of SNiP 23-02-2003. In addition, a national standard of the Russian Federation was developed, approved and put into effect by Decree of the Federal Agency for Technical Regulation and Metrology No. 1211-st dated October 25, 2013. This standard is amended in relation to ISO 13790:2008. This Russian standard is a regulatory document on annual heat and electricity costs of maintaining the microclimate on heated or cooled premises. Results. The technology has advanced, and now the construction market offers houses with seamless facades and improved sound and heat insulation. These are monolithic frame houses with good thermal insulation, since monolithic concrete is poured directly into the formwork on the construction site, lined with glass wool thermal insulation and clad with facade panels, which reduces heat loss from a building. Conclusions. The analysis of the energy consumption calculation method has proven an efficient tool to determine the heat demand of heating systems. The calculation allows to determine heat losses associated with the transfer of heat through an external envelope and the need for thermal energy. In other words, given that the data for each climatic zone is correct, including selected construction materials, thickness of enclosure structures with account for solar energy, and the proper use of modern intake-exhaust systems, the construction of buildings, featuring higher energy efficiency in the climatic conditions of Central Russia, is possible and absolutely realistic.

Energy-saving performance of respiration-type double-layer glass curtain wall system in different climate zones of China: Experiment and simulation

The development of energy-saving technologies for buildings is an important means of achieving carbon neutrality. The respiration-type double-layer glass curtain wall (RDGCW) is a kind of enclosure structure with natural air circulation and a shading function. The RDGCW provides energy saving, and it is being widely promoted and used in China. However, there is still a lack of relevant research on the energy-saving effects and operating strategies of the RDGCW throughout the year. In response, this paper describes experimental evaluation and numerical simulation. First, the energy-saving effects in an office building using an RDGCW in Tianjin during the winter were studied experimentally, and the real-time temperature changes in the RDGCW and the room were measured with high accuracy under different operating strategies. Second, because the temperature distribution and energy consumption in a room is affected by the air flow in the RDGCW and by outdoor meteorological parameters in a complex manner, this investigation developed a coupled model on the basis of TRNSYS and CONTAM. The simulation results were in good agreement with the experimental results. Third, the verified model was used to evaluate the annual energy-saving effects of the RDGCW under dynamic outdoor meteorological conditions in Tianjin. When the optimal operating strategy was adopted, the energy-saving effect of the RDGCW in comparison with single skin façade (SSF) reached 32.8% under summer conditions and 38.3% under winter conditions. Finally, the RDGCW system in typical cities (Changchun, Shanghai, Guangzhou, Kunming and Tianjin) in five climate zones in China was simulated for the whole year. Under the optimal strategy, the RDGCW achieved good energy-saving effects. The energy saving was 27.7–49.2% in summer and 25.6–46% in winter, in comparison with SSF.

Theoretical Study on the Relationship of Building Thermal Insulation with Indoor Thermal Comfort Based on APMV Index and Energy Consumption of Rural Residential Buildings

In the field investigation of rural dwellings, it was found that thermal feelings are significantly different with varied envelopes even under the same indoor air temperature, and this paper explores the phenomenon in simulation. Based on building thermal investigations in several villages of North China, a typical energy and environment simulation model for rural residences was developed using DeST, and the hourly parameters of temperature and humidity were used to calculate the adaptive thermal comfort (APMV) of the rooms. The results show that the main reason for the different thermal comfort at the same air temperature is the large difference in the inner surface temperature. By adjusting the insulation thickness of the envelope structure, the relationship between it and the APMV value is obtained. By adjusting the insulation thickness of the enclosure structure and getting the correlation between it and the APMV value, it is obtained that when the heat transfer coefficient of the enclosure structure meets 0.5 W/(m2·K), the indoors can be in thermal comfort. This paper considers that the indoor air temperature cannot represent the APMV to evaluate the indoor thermal comfort, and the APMV value should be used to evaluate the thermal comfort of the renovated building and calculate the corresponding energy saving rate.

Study on the design of heating and energy saving of enclosure structure of rural self-built houses

For severe cold areas, indoor heating in winter is very important, and it is also important to achieve energy saving and emission reduction in the heating process. This paper briefly introduced a kind of heating envelope structure, the geothermal energy-based phase change wall, and analyzed two rural self-built houses in Shangluo city, Shaanxi province. One self-built house was built without the phase change wall, and the other was built with the geothermal energy-based phase change wall by the municipal government. The results showed that the self-built house that adopted the phase change wall had a better heat preservation effect and relieved the indoor temperature fluctuation; after the heating equipment was turned on, the self-built house that adopted the geothermal energy-based phase change wall had a higher and more stable indoor temperature, and the power consumption during the experiment was less.

Experimental research and finite element analysis on anti-wind bearing capacity of ECC large-hollow rate wallboard

This paper investigated the wind resistance of high-toughness cement-based composite (ECC) wall panels with large hollow rates. Two large hollow wall panels were prepared for the test, one was a ribbed large hollow rate wall panel, and the other was an integral cavity large hollow rate wall panel. The test variable was whether there were ribs inside the wall panel. The test results showed that the flexural performance and crack resistance of ribbed wall panel were better than non-ribbed wall panel, which wan increased by 70 % and 47 %, respectively. In terms of resistance to deformation, ribbed wall panel also performed better, which was particularly evident in the cracking stage. Perform finite element analysis on the test process of two wall panels. There was a good correlation between the test results and the finite element results. Models of wall panel with different parameters included the height of rid and the thickness of wallboard were also established. Through experiments and finite element analysis, it was concluded that the two large hollow rate wall panels have reliable wind resistance and can be used as the enclosure structure of 200 m high-rise buildings. The ribbed large hollow rate wall panels can be applied to higher load requirements in the engineering environment.

Numerical Simulation Research on the Displacement of Ground Connecting Wall in Geological Excavation and Soil Remediation

Monitoring the changes of the retaining pile wall during the excavation of the deep foundation pit, and accurately grasping the side displacement changes of the retaining pile wall can effectively grasp the safety status of the foundation pit construction. In this paper, taking Guangfo Ring Road as an example, theoretical analysis, numerical simulation and other methods are used to study the influence of foundation pit excavation on the horizontal displacement and deformation of the ground connecting wall during the reinforcement of mixed piles in the area adjacent to high-rise buildings. Get the following conclusion : (1) With reinforced ground connecting walls and non-reinforced ground connecting walls, the horizontal displacement curve of ground connecting walls is roughly the same, showing a trend of change between the larger and the smaller ends. As the excavation depth continues to increase, the changing trend of the “bow” becomes more obvious, which is in line with the changing law of the enclosure structure. (2) After the mixing pile is used for reinforcement, the maximum horizontal displacement of the ground connecting wall is greatly reduced. Compared with the case without reinforcement measures, the horizontal displacement value of the ground connecting wall is 5.66mm, which is reduced by 6.23mm. The reduction ratio is 52%, indicating that the mixing pile has a great inhibitory effect on the horizontal displacement of the ground connecting wall. (3) By comparing on-site monitoring and numerical calculation data, the change trend of the wall horizontal displacement of the measured value and the simulated value is approximately the same. The measured maximum value of the monitoring section is 8.46mm, the simulated maximum value is 5.66mm, and the difference between the two is 2.8 mm, verified the rationality of the model, and provided some experience for the excavation of foundation pits to protect adjacent buildings.