Investigation On Evaporative Condensation Method For Zero Emission Of High Salinity Wastewater Drived By Low-grade Waste Heat

High salinity wastewater is present in the petrochemical papermaking industry.The discharge is significantly increased with the industrialization and urbanization.It is difficult to recycle.The direct discharge of high salinity wastewater is not only the waste of water-salt resources and serious environmental pollution,leading to water mineralization and soil alkalinization.The existing high salinity wastewater treatment technology has poor salt separation effect,high energy consumption,high cost,and cannot meet increasingly strict environmental protection requirements.The research on zero-emission treatment technology of high salinity wastewater has become particularly important.For the first time,the paper proposes a low-evaporation coupled absorption refrigeration high-efficiency condensing high salinity wastewater method to achieve zero emission.The innovative invention designed a low-grade waste heat to drive high salinity wastewater with zero-emission evaporative condensation system.The low-grade afterheat heating high salinity wastewater to promote low-temperature evaporation to humidify circulating gas air.Low-grade waste heat drive absorption refrigeration to wet air condensation water collection,evaporation condensation alternates.High salinity wastewater is concentrated to a certain extent for crystallization,crystalline salt classification and recycling resource utilization..Achieve the goal of "new process,zero emission,low energy consumption,high energy efficiency" for high salinity wastewater treatment.Low-temperature evaporation is used to avoid high-temperature corrosion and scaling;low-grade waste heat is used as heat source,and energy gradient is utilized to avoid waste of afterheat resources and improve overall energy utilization;the high salinity wastewater is classified and crystallized,and the crystals are classified and recovered for resource utilization to achieve zero emissions.The design model of evaporation condensing system for zero-emission of high salinity wastewater driven by low-grade waste heat.According to the high salinity wastewater treatment process,established a physical model for designing a zero-emission evaporative condensation system for low-grade heat driven high salinity wastewater.Establish a mathematical model of system design.And based on the C++Builder platform,a design software for the evaporation of condensing system with zero emission of low-grade waste heat driven high salinity wastewater was developed.The software has two modules,a high salinity wastewater evaporative condensation module and an absorption refrigeration system module.Study on the performance of evaporation condensing system for zero-emission of high salinity wastewater driven by low-grade waste heat.Based on the development software,through the calculation and analysis of variable working conditions,the influence of the inlet parameters of the evaporation chamber on the heat and mass transfer performance of the high salinity wastewater evaporative condensation system;the influence of the residual heat resource and the cooling water temperature on the absorption refrigeration.The calculation results show that when the inlet temperature of high salinity wastewater in the evaporation chamber rises from 40 °C to 60 °C,the latent heat exchange rate increases by 6.61 kW;the air inlet temperature rises from 10 °C to 35 °C,and the latent heat exchange rate decreases from 8.8 kW to 5.56 kW.By increasing the inlet temperature of high salinity wastewater in evaporation chamber,the import quality flow of high salinity wastewater,air quality flow rate,or reduce the air inlet temperature.It can effectively improve the latent heat heat exchange in evaporation chamber,that is,promote the evaporation of high salinity wastewater.In order to improve the efficient operation of the system;Increasing the low-grade waste heat inlet temperature,low-grade waste heat mass flow rate and lowering the cooling water inlet temperature can improve the absorption refrigeration effect.Through theoretical reearch on low-temperature evaporation and absorption refrigeration of high salinity wastewater,and the construction of high salinity wastewater evaporative condensation system,absorption refrigeration system and mathematical modeling.It provides a new process and theory for zero-emission treatment of high salinity wastewater.The visual computing software is developed to provide reference value for the promotion of zero discharge treatment of high salinity wastewater.