The Oilfield Wastewater Resource Utilization System Thermal Simulation

The paper is about of taking advantage of the multi-stage evaporation to reduce the saltcontent of the high salinity Wasterwater,making them to reach the feedwater’s standard ofinjection steam boiler or other steam generating devices.recycling the waste heat generated inthe production process of oilfield provides heating energy for multi-stage evaporation.First,comparing parallel,countercurrent and stream series connection multi-stage evaporationsystem gets the conclusion that the third type of system is the best of all,because it has manyadvantages:the first is that it has a higher operating temperature,the second is that it is noteasy to form filth,and the most important one is that the fluid within the system can flow inthe absence of external power.Based on the principle of conservation of mass and energy andsimplified the calculation of falling film evaporator’s heat transfer coefficient create a systemmodel.The mathematical model of n stages system is described by3n-2nonlinear equationsAnd then,solve the nonlinear equations by using Matlab programming.Second,analysis theeffct of heating temperature and the number of stage on system’s coefficient of performanceand tatal ratio heat transfer area.And heating temperature has impact on the evaporationtemperature,pressure,temperature difference etc of each stage of the multi-stage evaporationsystem.Confirming the system’s heating temperature (115℃)by effect between heatingtemperature and tatal ratio heattransfer area; Confirming the number of system stage (6stages)by relationship between equipment investment costs,annual operating costs and thenumber of system stage.Based on them to determine the unknown parameters of system.Analysis the energy distribution of optimized system by pinch analysis technology.Third,dsign two kinds of heat pump systems.One of them is consisted of flash can,jetpump,compression R245fa heat pump.It can use of the wastewater’s energy produced bysteam injection boiler.The other is composited of the first type absorption heat pump，compression R245fa heat pump，compression steam heat pump.It can take advantage of theenergy of oilfield wastewater.At last, compare the two systems on energy efficiency andeconomy.It turns out that the first heat pump system is better than the secod one.