Study On The Method Of Transferring Pulsation In The Exchanger Of Pressure Pulsation Energy And Its Working Characteristics

Since the development of reverse osmosis membrane desalination,there were still three problems of high energy consumption,high cost and high pollution in the SWRO.In order to better solve the "three high problems" in the SWRO,the paper combines the theory of pulsating spray drying and takes the harmful pressure pulsation in seawater desalination system as the research point,a method of coupling the reverse osmosis desalination technology with the pulsating spray drying technology is proposed through the pulsating energy exchanger.It is for transforming the harmful pressure pulsation in the reverse osmosis desalting system into beneficial pressure pulse in the spray drying salt making system.The harmful pressure pulsation in SWRO is transferred to the hot air in the spray drying salt making system and so the hot air can pulsate.Though does it,the efficiency of spray drying for salt can be improved.This method not only utilizes the harmful pressure pulsation energy of pulsating high-pressure seawater in the SWRO and saves the additional energy consumption to drive the pulsation of hot air,but also improves the production efficiency of the integration of desalination and salt making by pulsating hot air.If the method is used in the integrated production of desalination and salt making,it can realize zero discharge of concentrated brine and achieve the effect of double-effect energy saving and emission reduction.Meanwhile,the cost of seawater desalination can be reduced by economic benefits from salt making.Therefore,based on the previous research of the research group,the pulsating exchanger is first designed and optimized.And the prototype of the pulsating energy exchanger is developed.According to the developed the pulsation energy exchanger,the experimental platform of the pulsating energy exchanger is set up,and the working characteristics of the pulse energy exchanger and the effect of the pulsating spray evaporation are experimentally explored.The main contents of this paper are as follows:1.A new method to transfer the pulsating energy in the SWRO to the hot air in the spray drying process is proposed by means of the pulsating energy exchanger.The purpose is to transform the harmful pulsation in the SWRO into the beneficial pulsation in spray drying,so as to improve the efficiency of spray drying for salt making.2.According to the design scheme of piston-gear-rack valve disc type pulsating energy exchanger,the prototype of pulsating energy exchanger is developed.3.An experimental platform of pulsating energy exchanger is built and the feasibility of transmitting pulsation in pulsating energy exchanger is verified by experiments.4.The work performance of pipe system of high pressure and the system of fan andduct during operation was investigated.The results show that the experimental platform of pulsating energy exchanger is stable during operation when the pulsating energy exchanger is not work.5.The working characteristics of pulsating energy exchanger are explored.The results are as follows:(1)The working pressure range of the pulsating energy exchanger is determined.That is the starting working pressure is 2.5MPa and the maximum working pressure is 5.0MPa.(2)When the working pressure of the pulsating energy exchanger is 4.5MPa,the wind speed of the pipeline decreases to the minimum and will appear inflection point of the trend of wind speed change under the working pressure.(3)When the pulsating energy exchanger works,the rotational speed of the valve disc of the pulsating energy exchanger increases linearly with the increase of the working pressure of the pulsating energy exchanger.(4)The pulse energy exchanger will cause fluctuation of wind pressure in pipeline when it works.The fluctuation period of wind pressure is 1 s and it wouldn't change with the increase of working pressure of pulse energy exchanger.The fluctuation effect of wind pressure is the best when the working pressure of pulse energy exchanger is 3.5MPa.6.There are three impacts of the spray evaporation: the temperature of the hot water,the working pressure of pulse energy exchanger and the wind speed in the fan pipeline.According to the above three factors,the experiment of fluctuating spray evaporation is carried out successively.The experimental results show that when the working pressure of pulsating energy exchanger is 5MPa,the fluctuating wind speed in the fan duct is 6m/s and the initial temperature of the water temperature is 90?,the water evaporation of the pulsating spray evaporation is 11.70% higher than that of the traditional spray evaporation.