Design And Performance Research Of Mechanical Vapor Recompression Falling Film Evaporation System

Firstly, conduct an overall design of mechanical vapor recompression (MVR)evaporation system, and then remodeling and set up the experimental platform. This systemis driven by roots blower. The paper mainly introduces the principle and process flow ofMVR falling film evaporation system. For better research，experiment and theoreticalanalysis method are used. Besides, choosing water as the experimental material, theappropriate operational area under different evaporation pressure and the compression ratioare explored, then studied the relationship of the flow of secondary steam, water added，heat energy，electric power，specific moisture extraction rate（SMER），unit consumptionof power，coefficient of performance (COP) and evaporation pressure，the compressionratio. Finally we obtain the variation of performance Indicators.The results show that the flow of added water is account for3%to9%of the flow ofthe secondary steam.The flow of added water increases when the compression ratio rises,and the relationship between added water and compression ratio is linear.The flow ofadded water is almost invariant with the compression ratio in the evaporation of50～70kPa.Heat energy arises with compression ratio increases when evaporation pressure is fixed andheat energy arises with evaporation pressure increases when compression ratio is fixed.When the compression ratio is constant, the power consumption of system increases as theevaporation pressure rises，the evaporation pressure affects the growth rate of motor power,the greater the evaporation pressure, the greater the motor power increases; Whenevaporation pressure is constant，the motor power consumption and the motor power ofunit quantity steam increases obviously as the compression ratio increases. With theincreasing of compression ratio，SMER and COP reduces rapidly initially，then becomesbalanced. The optimum operation range of the system compression ratio is1.7～2.1. Theideal situation is1.9.Compared with monotype evaporator， double-effect evaporator，triple-effect evaporator，four-effect evaporator. The saving standard coal consumption are75.0%、63.3%、31.1%、8.2%. energy efficiency is basically the same compared withfive-effect evaporator, the amount of standard coal consumption was less than2%.Whenproducing1t steam, MVR system can save175yuan,105yuan,35yuan,15yuan,9yuan. Theoperating cost is closely to five-effect evaporator. Using Aspen Plus to establish the model of MVR system, and prove the credibilityusing the data of experiment. The results show that the simulation well matches theexperimental data.Then conducting some scale-up simulation. Choosing the evaporation of1t，3t，5t，relationship between power consumption，heat energy，COP and compressionratio are analyzed. Finally, the error of system are discussed.