Research On Waste Heat Recovery Andutilization Technology Of Ship Air Compressor Station

Energy shortages and environmental pollution have developed into issues of common concern to the world.Saving energy and reducing emissions,reducing energy consumption,and improving energy efficiency are the fundamental ways to solve energy problems.In China's industrial field,waste heat resources are abundant.Among a lot of waste heat resources,air compressors are the equipment with great potential for waste heat utilization,and nearly 85% of electric energy is discharged into the atmosphere as waste heat.Hence,experiments and related simulations on the comprehensive recovery and utilization of waste heat for the air compressor waste heat resources are conducted in this paper.The following researches have been carried out:(1)Firstly,according to the characteristics of oil and gas temperature during air compressor work,a set of integrated system for waste heat recovery is designed based on the principle of “mainly oil roads and supplemented by gas roads”.Based on this case,an experimental system of simulated air compressor waste heat recovery is designed and constructed,and the overall experimental of waste heat recovery is studied on this system.The experimental results show that when the exhaust pressure is certain,with the increase of the lubricating oil's temperature,the exhaust flow decreases.The lubricating oil carries most of heat,which accounts for about 79.5% of the total heat.The heat recovery of oil and gas is 327.73 KJ/min and 84.35 KJ/min respectively,when the exhaust pressure is 0.6PMa and the temperature of lubricating oil is 70?C,and when the oil temperature ranges from 65?C to 75?C,the water temperature can be increased by more than 20?C,the flow rate of hot water that can be produced is 2~4L/min under the studied conditions in this paper.Therefore,it is practically feasible to recover the waste heat of air compressor,and the heat recovery effect is remarkable.(2)Based on the experimental data of waste heat recovery,a simplified geometric model with the same corrugated parameters as the experimental element is established for simulation analysis to verify the reliability of numerical simulation by Fluent software,which is based on the reasonable simplification and assumption of conditions.The simulation results in heat transfer performance and flow resistance are in good agreement with the experimental results.In addition,considering the heat transfer characteristics of different corrugation parameters and the forces acting on the plate,the fluid-structure interaction method is used to calculate,and the heat transfer characteristics and the strain distribution on the plate under different structural parameters are obtained.The calculation results show that the comprehensive heat transfer performance is the best,when corrugation angle ?=60?,spacing ?=12mm,height h=5mm,and when the oil viscosity is high,the plate is subjected to a large flow load.Therefore,the heat transfer performance,flow resistance and the force on plate should be fully considered in the heat exchanger design.(3)In view of the dehumidification and drying of compressed air,a method of supersonic swirl separation technology based on the combination of supersonic nozzle and swirler is proposed for the dehumidification of compressed air in this paper,and the performance of this method for dehumidification is studied by related simulation and experimental.The simulation results and experimental results show that the airflow velocity increases and the temperature drops after the airflow passes through the nozzle,which provides a prerequisite for the gas-liquid two-phase flow to swirl separation and this method can effectively remove part of the water in compressed air and the degree of gas drying can be further increased to some extent.The maximum temperature difference between the inlet and outlet of the nozzle is 7~8?C,and the average dehumidification efficiency under different conditions is 45.7% and 51.3% respectively under the given nozzle size and the studied condition in this paper.The calculation results in this paper have an important reference function to the technical scheme of the waste heat recovery for ship air compressor station,the improved design for plate heat exchanger and the method of dehumidification for compressed air.