A Research On Energy Conservation Method Of Office Building In Tianjin

Energy saving and consumption reducing are extremely urgent under thepressure of global energy shortage and environmental pollution, and office buildingenergy consumption plays an important role in total energy consumption. Manydeveloped countries have issued relevant laws and adopted various technical measuresfor energy saving in office buildings, which has achieved good application effect.Similar standards have been put forward in our country as well, and they arecontinuously revised while the energy conservation work’s carrying on. Tianjin isamending Tianjin public building energy efficiency design standards to reach the goalof65%energy saving in public facility, and this paper conducts a quantitativeresearch on energy conservation of public facility in Tianjin area, which will help toprovide a data basis for the revision.Based on a survey of office building energy consumption in Tianjin area in2010,this paper selects a typical office building, which possesses various representativeparameters, to establish the energy consumption model in eQUEST. The influence ofenergy saving technologies on building energy consumption are studied by changingthe parameters related to the building, including building orientation, Heat transfercoefficient in the maintenance structure, Outside sunshade measures and window-wallratio; HVAC system energy saving measures, such as chiller COP, running numbersand frequency conversion control, improving pump and fan efficiency, cooling towerwith variable speed fan, exhaust air heat recovery technology and earthwise systemhave been set up to research their impact on building energy consumption. Annualenergy rate is calculated on full year energy consumption of air conditioning and heatsource. Conclusions are drawn as follows:Considering the change of whole year refrigeration and heat supply, and takinginto sufficient consideration the heat dissipation from indoor to outdoor in the summernight. The outer wall and roof materials of office building in Tianjin region shouldtend to heat preservation performance; Windowpane should acquire low heat transfercoefficient and high shading coefficient. four layers low-e glass have the bestenergy-saving effect among common glass types, and its annual energy rate is9.28%;Fixed visor faced south is the best outside sunshade measure to save energy. When the protrusion coefficient increased from0.1to1.0, its annual energy rate is1.30%.When the south face window-wall ratio changes10%, the annual energy ratecan significantly changes from4.41%to6.68%. Compared with other direction, southface window-wall ratio less affects the building energy consumption.Effects of energy saving measures in HVAC system are largely different fromeach other. When water chiller COP Improves an energy efficiency rate, its annualenergy rate changes from0.52%to0.89%. Selecting suitable cold energyconfiguration to match the requirement influents running number of water chillers, solarge cooling units with small cooling units could save about2%of annual buildingenergy than split cooling units; Frequency conversion control measures can reduce1.73%of annual building energy consumption. When the pump and fan efficiencyincreases10%, its annual energy rate changes from0.5%to1.2%. Variable speed fanused in cooling tower could save0.56%of annual building energy consumption thanfixed speed fan. Exhaust air heat recovery technology could save4.11%of buildingenergy consumption. Under the condition of guaranteed air conditioning effect, freezewater earthwise system could save0.76%to1.18%of cooling energy.