Research On The Performance Optimization Of The Steam Jet Pump System

The working fluid(high pressure steam)flowing in the nozzle can attains supersonic velocity.At the same time the nozzle forms vacuum.The gas in the vacuum vessel will be pumped into the mixing chamber by the steam.In there,the working steam and gas are exchanged of momentum and energy,and then are compressed in the pressure enlarger,and expelled from diffusion tube.The speed of the mixed gas reduce gradually and the pressure of them increase.Finally they are expelled to the atmosphere to realize the purpose of pumping.Steam-jet pump can be installed in low order or open-air.It is suitable for some occasions,for example,the no non-condensable gas content high or working vapor pressure is not stable.Although steam ejector pump has simple construction,its pumping mechanism is quit complicated,because many factors affect the gas flow.Now,with the increasing of industrial demand for vacuum pump,the development speed of vacuum steam is expedited.As technology improvement and innovation,its characteristic are also increasingly satisfy the needs of people.It is an important factor to reduce the co nsumption of the steam and water for promoting the development of the steam pump.The direct searching method is used in the multistage steam jet pump system to distribute reasonably the compression ratio of the pump for the design method of the minimum consumption of steam.Based on the calculation model of pumping and the design theory,the optimal result obtained through editing software is compared with the actual technical parameters.In this paper,the following works are done about the multistage steam jet pump in the pumping theory and system optimization.1)In this paper,they are studied that the composition of structure of single-stage and multistage steam jet pump,working principle,the pumping theory and the influencing factors of the steam pump.2)The different series of steam jet pump are discussed about energy saving.Whether to need the condenser is determined by determining conditions.The coefficient method is used in the compression and the direct searching method is used in the injection lever,that to allocate the compression ratio of the pump in order to achieve the purpose of energy saving.3)Based on the conditions of vacuum(the pressure and temperature of the working steam,the flow,pressure and temperature of pumped gas and the temperature of condensed water),the method of distribution of compression ratio is used to calculate the consumption of the working steam.The calculations are compared with the technical data of the actual system.4)The pumping model of Oku Yoshio and the model of the experimental data are adopted to calculate the consumption of the working steam The calculation results of two kinds of models are compared and analysed.By changing working steam pressure and vacuum degree,the energy consumption of the steam vacuum is further reduced.5)The structure of the tri-steam-jet pump are simply designed.