| Building energy consumption in China accounts for a relatively large proportion of total energy consumption,and HVAC energy consumption is an important part of building energy consumption.Enhancing the thermal insulation performance of the envelope structure can effectively reduce the energy consumption of the air conditioner.In addition,walls and roofs account for a large proportion of the area of the outer protective structure.Therefore,the research on cooling technologies for exterior walls and roofs is of great significance to building energy conservation.The built-in tube-type envelope cooling technology is a kind of cooling technology developed in recent years with the promotion of radiant cooling technology.It embeds fluid pipes inside the envelope of buildings such as floors,floors or walls,and is used in concrete buildings.The storage and transmission of cold energy are formed inside the components.In practice,the usual application is to provide cold water to the end of the active cooling by a high-temperature cold source.The built-in tube enclosure is used as the end of the radiant air conditioner.The embedded tubes are usually buried in the ceiling and floor.Based on this idea,the passive embedded pipe envelope cooling technology that directly uses lowgrade energy can be considered.First,the outer wall and roof are cooled to reduce the building load,thereby reducing the energy consumption of the active environmental control system.At present,there are few researches on the application effect of passive built-in tube-type external protection structure cooling technology.The research mainly focuses on the establishment of the built-in tube-type wall heat transfer model and the study of heat transfer laws.Based on the above background,this article has launched The following research work:First,based on TRNSYS simulation,the feasibility of the embedded tube cooling technology is studied.The built-in tubular envelope cooling technology experimental room was built to verify the accuracy of TRNSYS simulation.Error analysis and Bland-Altman consistency analysis were used to compare experimental and simulated values to verify the accuracy of the simulation method.Taking indoor operating temperature and energy-saving rate as the cooling effect evaluation index,the feasibility of cooling in different cooling periods and different climate zones of the embedded tube roof and external wall technology is analyzed and studied.It is concluded that when the pipes are arranged on the bedroom roof and external walls,the indoor operating temperature is reduced by 5.5℃ compared with the working condition without embedded pipes,The cumulative load reduction rate reached 48.2%,and the cumulative load reduction rate reached about 50% in different cooling periods and different climate zones.Secondly,a simulation study on the cooling effect and energy-saving potential of three typical residential buildings with different body shape coefficients for villas,bungalows and high-rises was carried out.The design load reduction rate and the cumulative load reduction rate are used as the evaluation index of the load peak shaving effect and energy saving effect.The research results show that the optimal pipe-inserting working condition for villas is roof +west outer wall and south outer wall pipe-inserting.The design load reduction rate of this working condition is 34.6%,and the cumulative load reduction rate is 54.4%;the optimal pipe insertion work for bungalows The condition is roof + west exterior wall and north exterior wall embedded pipes,the design load reduction rate is 23.3%,and the cumulative load reduction rate is 43.6%;the optimal condition of high-rise pipe insertion is roof + west exterior wall and north exterior wall embedded pipes.The design load reduction rate is 14.6%,and the cumulative load reduction rate is 30.0%.It shows that the larger the building shape coefficient,the better the cooling effect of the application of the embedded pipe technology and the greater the energysaving potential.It also studied the influence of climate zones on the energy-saving potential of embedded tubular roofs and external wall cooling technologies.The results showed that the three optimal building conditions have an average cumulative load reduction rate of 55%,45%,and 35% in different climate zones.the cumulative load reduction rate of each climate zone has little difference.It shows that the application of embedded tube cooling technology in different climate zones can achieve better cooling and energy saving effects.Finally,the sensitivity analysis of the influencing factors of the cooling effect of the builtin tubular roof and external wall cooling technology is carried out.The results show that the cooling technology of embedded pipes is greatly affected by the spacing and depth of embedded pipes,but is not significantly affected by the flow of water supply.Through orthogonal experiment analysis,the best design scheme of embedded pipe system parameters is as follows:water flow 400kg/h,buried pipe spacing 100 mm,buried pipe depth 100 mm.The energy-saving effect of the embedded tube cooling technology applied in different orientations of the building is studied,and it is concluded that the energy-saving effect of the unit embedded tube area in different orientations is the south outer wall,the west outer wall,the east outer wall,and the north outer wall in order from high to low.In addition,the larger the building form factor,the stronger the energy-saving effect of the same orientation. |
