Traditional negative pressure evaporation technology has problems such as low heat transfer efficiency,large equipment investment,poor vacuum stability,unstable water quality,and high cost of final exhaust steam condensation.An in-depth research on the theoretical basis and application condi-tions of micro-positive pressure evaporation has been conducted,and it has been proposed that the thermal energy balance factor Δqz is a key factor in controlling the stable operation of micro-positive pressure evaporation systems.The recovery of steam thermal energy carried by non-condensable gas dis-charge,as well as the thermal energy of condensed water and discharged concentrated water,is an im-portant measure to maintain the stable operation of MVR systems under micro-positive pressure condi-tions.The MVR plate falling film evaporation process operates under micro-positive pressure condi-tions,with a water mineralization degree≤30 mg/L.The heat transfer coefficient of the falling film evaporation plate is increased by more than 10%compared to micro-negative pressure evaporation,and the overall equipment investment is reduced by about 6%to 8%.The dosage of defoamers and pH regu-lators is also significantly reduced.By comparing the operating data of micro-negative pressure and mi-cro-positive pressure,it is found that micro-positive pressure control of evaporation process parameters has advantages such as better water quality,larger heat transfer coefficient,lower investment,lower energy consumption,and reduced chemical consumption.
关键词
MVR蒸发/微正压蒸发/板式降膜蒸发器/微正压控制技术/不凝气排放
Key words
MVR evaporation/micro-positive pressure evaporation/plate falling film evaporator/micro-positive pressure control technology/non-condensable gas discharge
维普
万方数据