Study On The Performance Of The Double Temperature Of Fresh Air Handling Unit In Temperature And Humidity Independent Regulation Air Condition System

At present,China's building energy consumption accounts for about 28% of the total energy consumption in the whole society,and the energy consumption of HVAC is about50%,so it is very important to adopt energy-saving technology in HVAC.The centralized air conditioning system mostly adopts the model of coupled heat air treatment,system of the indoor air by 7 ? chilled water cooling and humidification process,the existence of three questions: first of all,the demand for low temperature freezing water chiller COP is reduced,the second,the temperature and humidity coupling treatment,make indoor air temperature and humidity is difficult to meet the design requirements,the need to deal with to reheat the air dew point state,there is hot and cold offset phenomenon,in the end,installed in the interior of the surface of the heat exchange coil condensate,and condensed water on the surface coil are prone to bacteria,the worsening indoor air quality.In order to solve the above problem,domestic and foreign scholars put forward the temperature and humidity independent control air conditioning system,the system will be air cooling and humidification process decoupling in the process,all the moisture load borne by the fresh air unit system,terminal equipment only undertake indoor sensible heat load,the fresh air humidification performance of the unit is the key to stable operation of the whole system.Commonly used in the temperature and humidity independent control air conditioning system,fresh air units have liquid desiccant units,direct expansion turbine unit and puts forward cooling humidification,hot wet area meteorological conditions,the author of this paper,combining the use of temperature and humidity independent control air conditioning system,with doubletemperature table type cold fresh air unit performance is studied,the fresh air unit is composed of two level puts forward series,outdoor air into the first level first puts forward,using the 15 ? high temperature of chilled water for air cooling,then enter the second table cooler,carried out by the 7 ? low temperature of chilled water depth humidification process,the fresh air unit satisfies the requirement of fresh air temperature and humidity independent control air conditioning system.The specific research contents are as follows:To study the performance requirements of the air conditioning system with independent air-conditioning system in the hot and humid area,and to analyze the energy saving potential of the air-conditioning system in the hot wetland area independently.A building in Guangzhou as an example,the building annual energy consumption simulation,get the building indoor sensible heat and latent heat load,the sensible heat and latent heat load and fresh air,respectively with conventional heat coupling air treatment mode of fan-coil unit plus fresh air system and high and low temperature heat source temperature and humidity independent control air conditioning system,from water chillers,frozen water pump,cooling water pump,cooling tower and system terminal equipment five parts to carry on the analysis,the quantitative comparison of the system operation energy consumption of each part,double heat source temperature and humidity independent control air conditioning system in a hot wetland area energy saving potential of up to 19.89%.According to the temperature and humidity in the hot and humid area,the air conditioning system is designed to meet the performance requirements of the new wind unit.For temperature and humidity independent control air conditioning system of fresh air is analyzed,summarized the different forms of fresh air and realization method of the dual temperature cooling fresh air unit in the high and low temperature table cooler,filter and fan and the motor is designed,and produced new wind experiment prototype unit.Testing the the double temperature of fresh air handling unit under the condition of variable air volume and variable refrigerant flow thermal performance,to meet the design requirements of low temperature cooling flow control performance are analyzed,and the fresh air unit running effect in hot wetland area is evaluated.Enthalpy-difference using standard for high temperature cooling period of variable air volume,change of frozen water flow and variable air volume at the same time,freezing water outlet air of the three cases of parameter test,for high temperature heat transfer performance of the cooler,and its thermal performance is analyzed.In meet the design requirements,test and analysis of the variable air volume cases different pyrometer cooler water temperature on the effect of low temperature puts chilled water flow regulation,it is concluded that with the reduction of air volume needed to meet the supply status of low temperature cooling the lower section of the chilled water flow,when the air volume reduced up to 50% of the rated air flow,low temperature freezing water flow intable cooler only 45.1% of the rated flow can meet the requirements of air supply.To fresh units in spring summer working condition of high temperature and high humidity conditions of running performance was tested,and get the high and low temperature table cooler air parameters of imports and exports,analyzes the import and export of pyrometer tanks under different working condition of air enthalpy difference unit and the ratio of total enthalpy difference,it is concluded that using high temperature cold water cooling,air enthalpy drop proportion accounted for about the whole process of fresh air enthalpy drop of about 50%,has the high energy saving potential.