Research On Constant Temperature And Humidity For Investment Casting

With the development of modern industry and air conditioning technology,constant temperature and humidity air-conditioning with high precision and largescale is widely used. Constant temperature and humidity air-conditioning need largeair flow, high precision,continuous operation. Interference feature, building envelopecharacter, air distribution, air supply parameter, air exchange frequency, automaticcontrol strategy and air conditioning processing mode influent the control precision,energy consumption air-conditioning. This paper combines investment castingproduction process, studies indoor heat and humid load and air exchange frequency ofconstant temperature and humidity air-conditioning.Constant temperature and humidity system scheme is based on heat and humidload. This paper studied the desiccant process of workpiece in the investment castingprocess and gains the dynamic desiccant characteristic curve and related data: Itcantain speed desiccant, stablely desiccant and low speed desiccant. Different coatingpaint has different desiccant speed and moisure gain, workpiece average desiccantspeed is28.2g/h, maximum speed is100g/h.Air exchange frequency is an important indicator to ensure the precision ofconstant temperature and humidity air-conditioning. This paper makes numericalsimulation about how air exchange frequency will impact indoor heat and humidity ina large space. The result shows that air exchange frequency is6per hour in summer,12per hour in winter to make sure21±1℃,50±2%heat and humidity precision.In order to research the relationship between air exchange frequency, desiccantamount, heat and humidity precision, this paper separates mainly dry regions,simulates heat and humidity distribution under different desiccant amount and airexchange frequency. It concludes that in different desiccant amount, the precisionincreases with air exchange frequency and fits segmental cubic polynomial function;in the same air exchange frequency, precisions decrease with desiccant amount andfits linear relation. Though proper arranging axial flow fan to enhance flowdisturbance, it can improve precision and uniformity of air temperature and humidity.