Research On Landscape And Energy-saving Integrated Water Curtain System For Playgrounds

The proportion of building energy consumption in total energy consumption keeps increasing in China.Compared with that in 2000,the total building energy consumption has increased by nearly three times in 2016,among which public buildings takes the largest proportion.The public buildings energy consumption per unit area is 2.5 times and 3.4 times of those for urban residential buildings and rural residential buildings,respectively,thus it has become imminent to reduce energy consumption of public buildings.Because the public buildings in the fields of a entertainment and tourism use a large number of glass curtain wall external protection structures,the cold and heat loss is serious,and it is urgent to reduce the energy consumption and it's needy of landscape requirements.Based on the above two requirements,the author proposed a design concept which integrates both reduction in energy consumption of glass curtain wall by shading and the landscape demand,of which by integrating design of glass curtain wall outside the structure building and the water curtain landscape to meet the needs of landscape and sunshade.This paper established a model for water curtain radiation calculation,by the mechanism of water film absorption on solar radiation,and then the accuracy of the model is confirmed based on Ecotect software.Through the established calculation model,the synergistic relationship between water film thickness,dip angle,azimuth angle and solar radiation transmission of water curtain system is revealed.The influencing factors of air layer temperature drop are analyzed;through the micro-water film at the nozzle outlet The force analysis,the influence of wind speed and wind direction on nozzle exit angle and speed selection is shown.Finally,the actual project in Changsha,Hunan–Ice and Snow World is taken as an example to analyze the energy saving effect of the system.The research shows that the mathematical model of sunny-day water curtain radiation model established in this paper is accurate,and the relative error of hourly solar radiation transmission is within 10%which can be used to calculate the amount of solar radiation passing through the water curtain system.The water curtain system has a strong absorption effect on solar radiation,and the absorption of solar radiation by the water curtain system show an increase with the rise of the thickness of the water film,while the effect of water film thickness on solar radiation absorption shows an opposite trend,and water film with a thickness of 0.03 m~0.04 m can reduce 68%~78%solar radiation.The influence of the dip angle on the solar radiation transmission in summer and winter is quite different:in summer,the solar radiation transmittance in water curtain system shows a downward trend with the increase of the dip angle of the water curtain system,while it shows a rising first and then declining trends in winter water curtain system.The water curtain orientation has little effect on the water curtain system while azimuth angle within 0°~90°,and its influence on the solar radiation transmission in winter is slightly larger than that in summer.The temperature drop of the air layer will rise with the increase of the outdoor air temperature,and goes down with the increase of the water temperature(relative humidity of air)and the air flow rate,when the air velocity is 0.25 m/s,the initial air temperature is 39oC and the water temperature is 20oC,the temperature drop of the atmosphere can reach 3.6oC.Under the premise of ignoring the influence of the lateral wind on the water curtain system,the motion equation of water particle sprayed by the nozzle under the action of gravity and wind with specified wind speed and direction is given,which provides an evidence for the selection of the nozzle flow velocity and inclination of the water curtain system.For the landscape trail of the Changsha Ice and Snow World Project,according to the design parameters proposed by this paper,when the outdoor air temperature is 35.8oC,the solar radiation can be reduced by about 7.79×10~9 J,and without any refrigeration equipment,The fresh air temperature can be reduced by 2.2oC,which is a 26%reduction in fresh air sensible heat load.The landscape and energy-saving integrated water curtain system proposed in this paper combines the landscape design of glass curtain wall building with the building energy-saving design from the perspective of landscape energy-saving integration,which not only increases the decorativeness of the facade of the public building glass curtain wall,but also the energy consumption of the building is reduced,which provides a new idea for the energy-saving renovation of the glass curtain wall of public buildings.In addition,the model established in this paper enable the calculation of the solar radiation transmission of different materials at a certain inclination angle by changing the extinction coefficient,which will be great helpful in further study of shading facilities of the enclosure structure with a certain inclination.