026 Library Information Center of Dalian University of Technology in Liaodong Bay
Location: Liaodong Bay, Liaoning Province, China
Owner: Dalian University of Technology
Architect: Tianzuo Architecture Research Institute, Shenyang Jianzhu University: Liu Wanli, Zhang Lingling, Wang zhemin, Zhao weifeng, Bayin bulage, Zhong zhaokang, Hao ana, Ju yexin, Hou yu, Li keheng
Project type: Library
1. Form Layout Optimization——A Method of Form Generation of Cold Public Buildings Based on Climate Environment Simulation Analysis
Considering the connection between the core building of the campus and the urban space, the Library and Information Center is located in the northeast part of the campus in the overall layout. It is close to the main urban road in the east, sharing information resources with the science and technology and cultural industrial park, and connecting with the urban water system, forming the cultural image of “boat of knowledge” floating on water. As a starting project, the layout of the library and information center plays a leading and radiating role in the new area. However, the northeast part of the campus is empty and the urban road is wide and straight, which makes the building group of the library and Information Center face the dominant wind direction in winter. Under the attack of cold wind without shelter, the heat of the building outside is seriously lost.
In order to solve this problem, the research team proposed a method of generating public building form in cold regions based on climate environment simulation analysis — “Environmental AdaptiveDesign Method of Building Form”. The method includes three steps: analysis of environmental conditions, coordination of overall layout and topology optimization. Its principle is to use digital technology to obtain environmental condition information and carry out comprehensive analysis to determine the leading factors and related factors and their effect mechanism on building green performance. On this basis, the layout and form of the library information center are systematically optimized, so as to effectively control the heat dissipation of the building form, shield the cold wind, adjust the microclimate, and improve the comprehensive green performance of the building. This method is a new green building design method from the architect’s perspective, which is oriented by goal and effect, and considers building function and performance.
(1)Analysis of environmental conditions
Analysis of environmental conditions is the premise and foundation of architectural layout and form optimization design. It includes two aspects: the first is the analysis of natural environment conditions, mainly analyzing the geographical information and climate environment of the area where the building is located; Secondly, the analysis of urban environmental conditions, mainly including the spatial form of the surrounding area, road network structure, etc. We obtain relevant information through geographic information system, and use building performance analysis tools for systematic comparison and screening, ranking them according to their impact on the overall green performance of the building. Through the systematic analysis of the relationship between local climate conditions and building energy consumption by IES VE tool, it can be found that low temperature and cold wind in winter have the greatest influence on building energy consumption, which will directly affect the building energy-saving effect and environmental quality. Therefore, as far as possible to strive for sunshine, optimize streamline, improve the quality of the environment is the basic direction of the Library information center design, which is also the premise and foundation of the subsequent layout and form optimization.
(2)Overall layout coordination
The overall layout optimization of the Library information center has important green value. Onthe one hand, a reasonable building group relationship can avoid unfavourable climatic and environmental factors as far as possible and reduce the total energy consumption of the building group. On the other hand, it can shape a good external space environment of the building, optimize local microclimate and improve environmental comfort. Located on the shore of Bohai Sea, Liaodong Bay New Area is characterized by cold winter and high wind speed, which has a very negative impact on building thermal insulation and energy saving, and at the same time leads to bad microclimate and strong discomfort. Compared with adjacent teaching area group buildings, the functional composition and space requirements of the Library InformationCenter make it impossible to adopt a yard enclosure layout similar to the surrounding one. Therefore, rationally organizing the spatial relationship of the three buildings and reducing the width of the total windward surface of the buildings are the key measures to shield the cold wind, reduce energy loss and improve the environmental quality. Through THE CFDsimulation analysis of IES VE tools, the buildings were arranged in a north-south order with sufficient daylight spacing to achieve the best environmental adaptability and functional rationality. First, the relatively compact layout can effectively reduce the total windward area of the building group and minimize the adverse impact of cold wind on the building. Thirdly, the sequential layout can connect the main entrances located in the wind shadow area in series, to obtain the most economical traffic flow line and the most reasonable space organization, and realize the coordination of building function and performance. Finally, the sequential buildings form a windscreen interface, which reduces downwind speed and eddy current of the building, effectively improves the wind environment in the surrounding area of the building, and realizes the coordinated intervention of the building on the environment.
(3)Form Topology Optimization
Under the constraints of function, space,streamline and other architectural designconditions, the library and information centeradjusted the architectural form in the optimizationdesign to take into account the shape coefficientand cold wind adaptability. We use the method ofshape topology optimization to find the optimalarchitectural form, and use Grasshopperparameter chemical tool to continuously changethe shape of the building under the condition ofensuring the same topological properties. Withthe minimum shape coefficient and optimal windenvironment performance as the objectivefunction of screening, iterative and finally get theoptimized architectural form. The results showthat although the rectangular shape is regular, theshape coefficient of the same plane area is larger,the heat dissipation of the outer surface is more,and the eddy current will be formed at the edgesand corners, which has an adverse effect on thewind resistance of the building. Although theshape coefficient of the near circular volume issmall, there will be a large eddy between thebuildings, and the microclimate environmentquality is not good. The body mass coefficient ofcells obtained from the topological changes of thenear-circular body is also small, only 0.11, far lessthan other buildings on campus, which caneffectively control the heat loss of the outersurface of the building. At the same time, thebuilding layout along the wind direction caneffectively reduce the windward side of thebuilding, avoid the adverse impact of cold windinvasion and backward-facing eddy current, createa comfortable microclimate environment, and realize the bidirectional optimization of the shapecoefficient and wind environmental performance.
2.Innovation of Enclosure System – Research andDevelopment of Suitable Respiratory Double-layerCurtain Wall Technology and Texture Format ofGrid-type Building Interface
In this project, due to the requirements of urbanplanning, the library and information center islocated near the main road of the city, so theimpact of noise on the building is very serious. Inthe architectural design, the double-layer curtainwall combined with characteristic buildinginterface texture is adopted to achieve the dualgoals of sound insulation, noise reduction andrepresentation of wetland regional image.Meanwhile, on this basis, environmental comfortindexes such as thermal insulation, ventilation andlighting are improved.
As an important supplement and alternative totraditional fossil energy, new renewable energyhas attracted more and more attention in Chinaand gradually stepped out of the laboratory. It hasrealized the significant change of input-outputratio. It has been applied in many practicalprojects, which has become a sustainabledevelopment trend. In this project, consideringthe project cost, local geology, daily work-rest anduse mode of the school, the complementaryheating mode of ground-source-heat-pump andurban-heat-network is adopted in the R & D anddesign.
There is a good reserve of geothermal resourcesand a high groundwater level in the Liaodongwancampus of Dalian University of technology. whichis conducive to the supplementary flow of energyin the soil. It is a geothermal demonstration areaand a prerequisite for the application ofgeothermal heat pumps. Due to the lowtemperature and long duration in the extremelycold period in winter, the application ofgeothermal heat pumps system has somelimitations. In order to meet the comfort of theindoor environmental, the heat pump systemneeds to operate fully in extremely cold period,and even increase the electric auxiliary heating,the actual energy consumption will increasesignificantly. Considering the organizationalcharacteristics of teaching-learning life inuniversities, the coldest and hottest months ofeach year are winter and summer vacation respectively. The closing period is from the nightto the morning when the temperature is thelowest every day, which has low requirements forthe indoor thermal environment. Low temperatureoperation can be adopted to alleviate thecontradiction between climate and energyconsumption. Therefore, the use of geothermalheat pumpss in University Book-informationCenter is conducive to maximizing its advantages.
The use of geothermal heat pumps system in thisproject also has two major characteristics. First, itcan be used in winter and summer, and it can becollected in winter and supplemented in summerto ensure energy conservation. The geothermalheat pumps system of the libraryinformationCenter provides a heat source with a supply andreturn water temperature of 55 / 45 ℃ in theheating season, a cold source with a supply andreturn water temperature of 7 / 12 ℃ in therefrigeration season to meet the dual-purpose ofcooling and heating of the building indoor airconditioning system. While cooling in summer,the replaced heat can be replenished into theunderground soil, so as to achieve the reservebalance and inexhaustible circulation ofgeothermal energy, ensure the long-termsustainable and efficient operation of geothermalheat pumps. Second, it can be used flexibly in thetransition season to improve the environmentalcomfort of the whole year. Compared with theseasonality strictly observed by the central heatingnetwork in cold areas, the geothermal heat pumpssystem owned by the campus has a more flexibleuse mode. In the period when the two transitionalseasons of spring and autumn are connected withwinter, it can be used flexibly according to theclimate change to ensure that the indoorenvironment maintains a high degree of comfortthroughout the year.
According to the functional requirements and theapplication results of cavity guidance and controltechnology, the three single buildings of theBook-Information Center are equipped with large-scale public shared spaces such as halls, atriums ofdifferent sizes. When used in winter, the heat inthe bottom space is easy to transfer upward. Inorder to ensure the thermal comfort of publicspace, geothermal coil system is set on theground of shared space in three single buildingsto assist heating. Therefore, the geothermal heatpumps provides heat source for the airconditioning system, and the Urban Heat-supplying System is introduced to provide heatsource for the geothermal coil system, forming acomplementary heating mode.
The outstanding advantage of the complementaryheating method of geothermal heat pumps andUrban Heat-supplying System is mutual “peakshaving”. It is reflected in different ways in short-term and long-term use. In short-term use, thecurrent urban heat supply network is charged byarea. The area used in the shared space of theBook-Information Center is fixed every year, andthe payment amount is also fixed. Then, the peakis cut by the geothermal heat pumps system, andthe use power of the geothermal heat pumps isadjusted according to the changes of outdoortemperature, so as to save electric energy. Inlong-term use, the development trend of urbanheat supply network in the future is to chargeaccording to the amount. The geothermal heatpumps system is mainly used. The urban heatsupply network is shaved peak. According to thechange of outdoor cooling and heating, adjust theon-demand heat extraction from the urban heatsupply network to avoid waste and reduce theheating cost in winter.
The geothermal heat pumps system uses cleanenergy and has no pollution to the environment.Although the operation of geothermal heatpumps system needs power support, the overallaccounting economic and environmental benefitsare far better than the simple use of urban heatsupply network heating. The comprehensive costadvantage is more obvious in summerrefrigeration. The complementary heating form ofgeothermal heat pumps and urban heat supplynetwork after collaborative optimization isconservatively estimated to save 30% of the costevery year. At the same time, it can save 30% ofthe cost of air conditioning units and otherequipment.
The annual conventional energy substitution ofgeothermal heat pumps used in the project is543.41 tons of standard coal, carbon dioxideemission reduction: 1342.22 tons / year, sulfurdioxide emission reduction: 10.87 tons / year, sootemission reduction: 5.43 tons / year, with goodenvironmental benefits. The analysis shows thatthe test results are consistent with the softwaresimulation results in the design stage, theindicators reach or even exceed the expectations,and the effect of the integrated application ofgreen technology is outstanding. The monitoring also selects the other three representativebuildings in the campus as a comparison, and theresults show that the results of the project areahead in all aspects.
1.Enhance thermal insulation performance andcontrol construction cost
When the double-layer curtain wall system isapplied in the south, under normal conditions theindoor and outdoor temperature difference is onlymore than ten degrees, and it is rare to see morethan twenty degrees. The inner and outer doublelayers adopt hollow glass curtain wall andcooperate with low-E film, which can fully meetthe requirements of thermal insulation. In thenorth, during the heating season, the indoor andoutdoor temperature difference is usually morethan 40 degrees, and the comprehensive cost ofusing double-layer insulating glass curtain wall ina large area is very high. Therefore, R & D focuseson selecting alternatives to improve thermalinsulation performance.
(1)Analyze the working principle of keytechnologies，Determine the principle of materialselection
On the premise of using double-layer glasscurtain wall, the double-layer curtain wall insouthern focuses on meeting the needs of heatinsulation. Generally, the “shading Low-E film” isselected to be set in the outer layer of the double-layer curtain wall. Using the characteristics of itsshading coefficient SC ＜ 0.5, it prevents most ofthe solar heat energy from entering the room andreduces the energy consumption of airconditioning in summer. Compared with theconventional glass curtain wall, the energy savingcan reach 38% – 60%.On the contrary, in thenorthern cold areas, it is necessary to select “highpermeability Low-E film”, with its shadingcoefficient SC ≥ 0.5, which is set on the inner layerof the double-layer curtain wall to prevent theexternal loss of indoor heat energy in winter. Itcan be seen that there are great differences in theaction mechanism of double-layer curtain wallbetween the South and the north. The design ofdouble-layer curtain wall with heat insulation inthe South as the core goal focuses on the outercurtain wall. On the basis of setting low-E film andshading components, it is suitable to adopt thescheme of glass curtain wall inside and outside.The double-layer curtain wall in northern coldareas with thermal insulation as the core goal needs to focus on ensuring the thermalperformance of the inner curtain wall to avoidindoor heat loss. When facing the extremely coldweather of -20~-30℃ outside in winter, althoughthe theoretical value of thermal insulationperformance of double-layer insulating glasscurtain wall with low-E coating can still meet thestandard. However, from the actual caseinvestigation, it is always difficult to completelysolve the problems of air tightness and coldbridge of glass curtain wall due to constructionaccuracy, material aging and other reasons,reflecting that glass curtain wall is not the bestchoice for inner curtain wall system. According tothe experimental calculation, the air interlayer ofthe double-layer curtain wall can obviously absorbthe solar heat energy to warm up and keep warmin winter. Relatively speaking, the main function ofthe outer curtain wall is to enclose the airchamber, and its own thermal insulationperformance does not play a key role in the wholesystem. Reducing the technical standard of theouter curtain wall can greatly reduce the cost, buthas little impact on the overall performance of theexternal enclosure system. At present, the cost ofconventional glass curtain wall is about 1200-1800yuan / m2, and the cost of double-layer breathingglass curtain wall system is 2500-4000 yuan / m2.The investment cost of one-time construction isseveral times higher than that of traditionalmasonry with insulation layer, which has greateconomic pressure. To sum up, the breakthroughof adaptive breathing double-layer curtain walltechnology lies in the R&D of inner curtain wallsystem that meets the double standards ofeconomy and technology. Moderately reduce theperformance requirements of the outer curtainwall to improve the overall cost performance.
(2)Integrate appropriate technologies,Determinethe best technical measures
After determining the respective insulationrequirements of the inner and outer curtain walls,we can put forward a targeted technical scheme -researching a “dry wall” system to replace theinner curtain wall. The traditional buildingenvelope is usually built with blocks, and itsconstruction process includes wet operation. Theconstruction in the cold area of the northern isgreatly affected by climate conditions.Comprehensively studying and judging theconstraints of thermal insulation performance,project cost, construction cycle, facade design and other factors, the self-developed composite “drywall” system is adopted for the inner curtain wall.The “drywall” is a curtain wall system with a totalthickness of 400mm. The main structure is 60mm× 40mm steel tube horizontal and longitudinalkeel is fixed on the main structure frame of thebuilding. The inside and outside are blocked by12mm thick high-strength cement board andfilled with 150mm thick rock wool（ λ≤0.050[W/(m × K) ], heat transfer coefficient ofmain section of wall km = 0.40 [w / (㎡) × K) ],average heat transfer coefficient of wall KP = 0.44[w / (㎡) × K)] <0.5[W/(㎡ × K) ], which plays amajor role in heat preservation. The window sashcan be opened on the wall for daylighting andventilation. The construction of the composite”dry wall” system is simple and fast, whicheffectively shortens the construction period.According to the simulation, its thermal insulationperformance is more than 10% higher than that ofthe external wall system of ordinary lightweightaggregate block and external thermal insulation.The construction of the composite “dry wall”system is simple and fast, which effectivelyshortens the construction period. According to thesimulation, its thermal insulation performance ismore than 10% higher than that of the externalwall system of ordinary lightweight aggregateblock and external thermal insulation, the role ofthe closed air chamber cannot be calculated in theenergy-saving calculation, but it can be seen inthe software analysis and actual environmentalcomfort detection that it further improves thethermal insulation performance of the “dry wall”system. The overall average unit weight of thecomposite “dry wall” system is less than 20% ofthe block exterior wall system, which reduces theself-weight of the enclosure system and effectivelysaves the cost of the building structure system. Interms of construction cost, the cost of “dry wall”system can be controlled at 450-500 yuan / m2,which is equivalent to 35% – 40% of the cost ofsingle-layer Low-E glass curtain wall.
As the outer curtain wall mainly plays the role ofenclosing the air chamber, the system with lightweight, simple structure, durability and costbalance shall be selected as far as possible.Considering the skin hazy image proposed in thearchitectural image conception, the polycarbonatehollow board system is selected. Polycarbonatehollow board, commonly known as sunshineboard, is extruded and formed. It is usually double-layer structure or multi-layer structure. Itsimportant characteristics are light weight, lighttransmission, durability, super strength, flameretardant, bendable, sound insulation, obviousprice advantage – only 15-20% of the cost of glasscurtain wall. However, in the advanced stage oftechnical design, the state issued the DocumentNo. 65 of the Ministry of Public Security, whichrequires that the outer protective materials ofcolleges and universities must meet the fire gradeA (non-flammable), resulting in the need torethink the technical scheme.
After comprehensive analysis of other materials,the U – shaped glass outer curtain wall system isredetermined. U-shaped glass is a unique glassprofile produced by calendaring method, whichhas good properties. Because of its channel steelsection, its mechanical strength and stiffness aregreatly improved compared with ordinary flatglass. It has the properties of acid-base resistanceand high temperature resistance, and canwithstand the test of various climate changes. Theheat insulation effect of double-layer buckle isbetter, which is suitable for hot and cold areas; Inaddition, it also has the advantages of lightresistance, anti-aging, good fire resistance (class Anon-combustible), easy to clean with water and soon. The project adopts single-layer 7mm thick U-shaped glass, and the vertical frame of curtain wallis cancelled by taking advantage of its ownstructural performance, which further saves thecost. The comprehensive cost is about 1000 yuan /m2, which is about 30% lower than the cost ofglass curtain wall.
After the design is completed, the German greenbuilding evaluation software DÄMMWERK is usedfor calculation. The software adopts EnEV system.The latest regulation in the project design isEnEV2009, which can accurately describe andcontrol the actual energy consumption of thebuilding. Through the specific model calculationof the scheme, the operation energy consumptionof the building in the service life – 38.4kwh/m2a isobtained. It is far lower than the energyconsumption level of 90-120 KWH/M2A of publicbuildings in China at that time, and belongs to theenergy-saving green building.
2.Optimize equipment structure and reducemaintenance cost
As the project is located in the severe cold area,the wind and snow invasion, freezing, thawing andfrost heaving pose a great threat to the long-term normal operation of the openable ventilationcomponents of the intelligent curtain wall system.It is easy to cause the opening and closing of theventilation components out of control, seriouslyaffect the use effect of the intelligent airconditioning system of the curtain wall, andbecome an important reason to hinder the wideapplication of the traditional intelligent double-layer curtain wall system in cold areas. In thissystem, the principle of passive energy-savingtechnology is used to optimize the setting of thecurtain wall cavity and ventilation components. Onthe one hand, the depth of the air buffer cavitybetween the inner and outer epidermis isincreased to 650-700mm. Compared with thedouble-layer curtain wall with a general cavitydepth of 500mm, the “chimney effect” of the deepcavity is more significant, and the air flow speedand flow are increased by more than 30%. Thefunctions of air flow ventilation and heatdissipation in refrigeration season and airinterlayer heat storage and warmth preservationin heating season are brought into full play, so asto improve the air passive regulation ability ofdouble-layer curtain wall system. On the otherhand, the number of air vents on the outer skin ofthe curtain wall is reduced, and the position andsetting mode of upper and lower air vents areadjusted by using the advantage of increasing airflow rate after cavity enlargement. The upper ventis set inside the U-shaped glass and the lowervent is set on the lower bottom of the curtain wall,so that the opening and closing components ofthe vent can avoid the erosion of directly facingthe wind and snow, reduce the chance of freezingand thawing of snow water on components, andreduce the probability of damage to mechanicalmembers of curtain wall.
Intelligent design fully takes into account thedemand of climate characteristics in differentseasons for functions of building skin ventilation,insulation, building fire protection and smokeexhaust. The electric opening window and louverlinkage method is adopted to achieve the overallopening and closing, fire-fighting linkage,partition controllable, extensible and otherrequirements.
3.Implement the LCA concept and save operatingcosts.
Compared with ordinary campus buildings, theBook-Information Center has applied a largenumber of new technologies in energy-saving technology, energy-saving materials, developmentand utilization of new energy, intelligent controlof equipment and so on. It can effectively save theoperation cost after putting into use and improvethe comprehensive economic benefits of campusbuildings in the “whole life cycle”. It is mainlyreflected in the following three aspects:
(1)Saving energy consumption
Through the research and application of efficientwall and roof insulation materials, energy-savingbridge broken aluminum alloy doors, windowsand curtain walls, and intelligent adjustmentdouble-layer curtain wall technology system, theheat loss of the building is reduced. Adjust theoperation mode of air conditioning andventilation equipment through intelligent control,frequency conversion technology and pressuretransformation technology, and reasonably adjustthe equipment operation temperature and airvolume according to the use of campus buildings,so as to avoid unnecessary waste of power andheat energy. Through the development of newrenewable energy such as geothermal heatpumps, the building heating and cooling, whichaccounts for about one third of the totalconstruction area of the campus, are solved, andthe consumption of heat and electric energy isgreatly saved. Through the research anddevelopment of sewage treatment, biochemicaldegradation and regeneration and reclaimedwater reuse technology system, the valuable waterresources are recycled in the campus space, whichnot only reduces the water demand of theUniversity for the city, but also reduces thedischarge and treatment pressure of sewage onthe municipal pipe network, and realizes theimprovement of the overall environmentalbenefits of the new area.
(2)Reducing equipment failure
According to the characteristics of regular andstable using-time of campus buildings, throughthe application of intelligent control technology, alarge number of equipment such as airconditioning, ventilation, water supply andheating can realize variable frequency and variablepressure operation. The working time andintensity of the equipment are shortened, whichcan effectively reduce equipment failure,equipment loss, maintenance cost and resultingwaste of resources. New water-saving appliancesare also used in toilet sanitary facilities, which alsohave the advantages of durability, less failure, less leakage and waste, and save operation costs.According to the technical and economicconditions in the severe cold area of Northeast,optimize the technical system of intelligentdouble-layer curtain wall, form a more targetedand appropriate energy-saving technical system,reduce the equipment failure rate and save theoperation and maintenance cost.
(3)Improving management efficiency
With the overall operation of the campusintelligent control system, remote control can berealized. It can realize household metering andremote meter reading of domestic water, directdrinking water, reclaimed water, hot water,heating and power, and all-round monitoring andscanning without dead angle on campus, and cansave the human and material resources of campusmanagement, improve management efficiencyand reduce management cost.
(4)Easy to recycle
At present, the whole life cycle theory ofarchitecture has brought architectural design andconstruction, operation and maintenance, renewaland demolition and other links into a whole andcontinuous process, emphasizing thecomprehensive evaluation of the buildingtechnology system. For the application prospectof building envelope system in severe cold areas,we not only need to pay attention to the cost ofone-time construction and daily operation, butalso whether it is conducive to recycling hasbecome an important evaluation standard. Thedouble-layer intelligent curtain wall systemapplied in the Liaodongwan campus project ofDalian University of technology has good renewal,transformation and recycling performance. Theouter U-shaped glass skin is fixed by thehorizontal channel steel guide rail, which isconvenient for installation and removal, and hasbetter recycling rate than the traditional glasscurtain wall. The light steel structure skeleton, rockwool insulation interlayer and cement sandwichboard of the inner “dry wall” system can berecycled, and the demolition difficulty is also low.At the same time, the inner “dry wall” system canbe cut and expanded according to the use needs,which has a good possibility of renewal andtransformation.