Sea water Desalination LT-MED driven by diesel engine exhaust waste heat Content Shortage of water resources and possible solution Seawater desalination LT-MED driven by diesel engine exhaust waste heat Demonstration project Services and equipment Shortage of water resources Shortage of water resources Offshore platform Ocean ship Island far away from the mainland Water transport Rainwater collection Seawater desalination RO (Reverse osmosis) LT-MED(Low temperature multi effect distillation) Common problems High energy consumption and high cost
Possible Solution RO Diesel generators are often used for inhabited islands to supply power. Reverse osmosis (RO) desalination devices driven by electricity is used to produce fresh water. Generators RO desalination device Fresh water MED LT-MED is characterized by a series of horizontal tube spray falling film evaporator in series, and the highest evaporation temperature is less than 70. Every effect evaporation temperature are lower than the previous effect, so the production of distilled water is several times than the heat source. A typical LT-MED desalination schematic diagram
Possible Solution Technical comparison LT-MED RO Operating temperature <70 Room temperature Thermal energy Steam or hot water None Electric energy 2-5 kw.h/m3 5-10 kw.h/m3 Engineering conditions Raw water requirement The utilization rate of raw water Steam or hot water, and electric energy Low pretreatment requirements, turbidity<50 NTU Only electric energy High pretreatment requirements, SDI<5, turbidity<1 NTU 40 %-45 % 20 %-40 % Effect of seawater temperature little Significant, need to be heated sometimes Operational flexibility 40 %~110 % flexibility Operation and maintenance service life Water quality Simple maintenance, cleaning every1-2 years > 15 years TDS<10 ppm,high quality for drinking complex, cleaning every 1-2 month Membrane replacing every year, 10 years for the main TDS<500 ppm,only for domestic water Advantages and disadvantages RO:Relatively low energy consumption ; High requirement for raw water; Low fresh water quality ; Complex maintenance; LT-MED: Relatively high heat requirement; Low requirement for raw water; High water quality; Convenient maintenance; LT-MED driven by diesel engine exhaust waste heat Low efficiency of diesel generator Plenty of waste heat
LT-MED driven by diesel engine exhaust waste heat LT-MED driven by diesel engine exhaust waste heat Waste heat recovery of diesel generator; The drainage system; Distillation system; Control system Cost comparison for a 100 m 3 /d desalination system Water LT-ME(waste heat) RO transport Chemical consumption / raw materials / 0.02 0.721 2.43 Yuan.m -3 Thermal / fuel consumption / Yuan.m -3 0 0 12.08 Power consumption / Yuan.m -3 3.214 7.571 0.954 Maintenance cost / Yuan.m -3 0.561 2.46 2.602 Membrane replacement / Yuan.m -3 0 0.682 0 Equipment depreciation / Yuan.m -3 3.63 2.124 3.636 Tons of water cost / Yuan.m -3 7.425 13.56 21.702 Comparison basis Electricity price: 0.9 Yuan /kw.h; Equipment depreciation: 15 years; Water transportation distance: 50 km Higher equipment investment for LT-MED driven by diesel engine exhaust
waste heat equipment investment: RO-600,000 Yuan, LT-MED-800,000 Yuan; No cost for waste heat, thus significantly reducing energy consumption of LT-MED, cost saving of 4-6 Yuan/m 3 Demonstration project A 60 m 3 /d desalination system using waste heat from diesel engine, in Guishan Island, Zhuhai, China When the diesel engine runs the loading of 600 kw or higher, the fresh water output is 2.5 tons / hour (equivalent to 60 tons of water per day); The fresh water per ton consumes less than 3 KW h; the desalination rate is greater than 99%, and the effluent quality of the water meets the national standard for drinking water (GB5749-2006). 4 Effect of tower low-temperature multi effect distillation device, the overall size is 2.5 2.0 4.0 m; a total weight of about 6 tons, main equipment material is made of 316L stainless steel, the service life is up to 15 years. Services and equipment Serialization : We provide a series of seawater desalination equipment according to the power of diesel generator Power of diesel generator :300 kw 1500 kw; Water production of sea water desalination:15 m 3 /d 120 m 3 /d; Modularization:Integrated and compact for the equipment according to the project condition. Other service Comprehensive recovery of cooling water and flue gas waste heat to increase water yield Multi-generator parallel connection