Calculate The Air Conditioning Cooling Load Of Evaporative Building Envelope And Analyze Its Energy Saving Potential

With the promotion of energy-saving emission reduction policies in China,low-energy,low-pollution air-conditioning technology is widely used,evaporative cooling technology with energy efficient cooling characteristics in the construction of air conditioning has a better application prospects.Due to the lack of corresponding reference design data,the current air-conditioning cooling load calculation of the building envelope does not take into account the effect of the evaporative cooling of the wetted structure on the cooling load of air conditioning.In this paper,a simplified method for calculating the cooling load of air conditioning for the envelope of the evaporative building is presented,and the energy saving and emission reduction potential of the evaporative building envelope is analyzed.Firstly,taking the evaporative wall model as an example,the formula for calculating the effective comprehensive temperature is derived from the point of heat and mass transfer.The outdoor meteorological paramete rs are selected reasonably and the dry bulb temperature and wet bulb temperature must be consistent.Deduce the air conditioning cooling load calculation fo rmula of evaporative building envelope by FDR method.Analyzed and compared the air conditioning cooling load characteristics of different moist building envelope under different temperature conditions through MATLAB programming calculation,which find that the value of overall air conditioning cooling load is larger under dry bulb and mean coincident wet bulb temperatures condition,hence the dry bulb temperature should be selected as the temperature parameters in practical application.Combining with the characteristics of climate zoning in China,calculated air conditioning cooling load of evaporative envelope of building in four typical cities including Beijing,Shanghai,Guangz hou and Urumqi,which indicate that the evaporative envelope of building has a great potential of energy saving especially in northwest of China like Urumqi.Secondly,the evaporative building envelope of different orientations,structures and thicknesses is calculated and analyzed,the results show that cooling load of east wall and west wall are the largest,and the cooling load reduction rate of south wall is the most;With the increase of the thickness of building exterior insulation layer,the air conditioning cooling load of building envelope will decreased,but the energy saving effect will be reduced,combined with the energy saving efficiency and economy,insulation layer thickness should not be too thicker.Lastly,energy conservation and emissions reduction of typical city are calculated through examples,and water consumption is estimated,find that evaporative building envelope in different climate zones have large ability of energy conservation and emissions reduction.The four climate zones are mentioned in this paper,the evaporative cooling effect of northwest cold region is best,as well as the energy saving potential,but the water in northwest is precious,so we don't recommend using evaporative cooling method,only used in hot weather of the all year;Hot summer and cold winter of south area have a long hot summer days,energy conservation and emission reductions are best in the whole year,which are the most suitable for evaporative building envelope.