Analysis Of LT-MED On Dynamic Parameters And Experimental Research

Now the global water shortage crisis problem brings big threat to the economic development and common people's lives improvement. And the seawater desalination is a useful way to solve this problem. Because the low temperature multiple effect distillation (LT-MED) system has many advantages over multi-stage flash (MSF). Such as, lower operational temperature and less manufacture cost. The more important competition is that the LT-MED and the power plant can be built together which is in order to produce the water and electricity at the same time. More and more professors and engineers are doing some research on the LT-MED.The performances of LT-MED system which is operated on dynamic parameters are calculated in more detailed and the results are analyzed. The different inlet temperature and the salinity of seawater and the different temperature of heating steam are taken into account. And the fall of the heat transfer coefficient caused by tubes scaling in evaporators and the boiling point elevation (BPE) are also considered. The temperature drop caused by the demister and the connected ducts are calculated in detailed. The results of analysis and discussion in this paper provide a reference for the practical desalination engineering project.The next part of the paper is to calculate the exergy loss and the exergy loss percentage. The four units of exergy loss mathematical model including evaporator, pre-heater, flashing box and final condenser are built. The results show that the majority of exergy loss is caused by the thermal temperature difference in evaporator and the cooling seawater discharge. The exergy loss caused by the thermal temperature difference in the evaporator can be reduced by the reasonably designed the tubes and spray system.A LT-MED experimental research system with five effects is built and is assembly in vertical way. The structure of the system is more compatible compared with the traditional ones. The vacuum test shows that the system is well designed and the performance of the experimental research instrument system is guaranteed. The experience on the LT-MED system building will be a great help to develop the LT-MED technology in practical engineering in the not long future in china.