The Establishment Of MVR Heat Pump Drying System And Constant Speed Experimental Study Of Drying Sluge

Drying is a solid-liquid separation process,Which commonly used operation unit, as the high-energy consumption and the drying efficiency is low, the energy crisis is increasingly aggravating, To design and develop a new low energy consumption of drying system is imminent. The mechanical vapor recompression technology using evaporate compressor to compress secondary steam input a amount of work, Secondary steam was compressed to the heating thermodynamic state. only consume a small amounts of electrical work, as its low operating cost, convenient maintenance, they were mature applied in desalinating seawater and evaporation concentration. But the study of MVR technology application in drying is rarely.This article will apply MVR in transmitting drier, have done parts of job:Base on the MVR heat pump drying system. Analysis the energy balance and mass balance process, thermal process to MVR system has carried on the preliminary theoretical analysis and calculation. simulated the Drying pressure is 80 kPa, the compression ratio is 2, the results show that the system of substance compression unit power consumption only need 311 kJ/kg, could recycle the condensation latent heat of 2346 kJ/kg, secondary steam temperature increased 19.9℃, the recycling heat and input heat power of the work ratio is 7.54, energy utilization efficiency is improved; The same drying preesure under different compression ratio, and the same compression ratio under the different dry pressure change law of heat pump system performance are simulated, the results show that on the same drying reduce pressure, as the compression ratio increase, the COP and SMER of MVR heat pump drying system were increased, Under the same compression ratio, as the drying pressure increase, the performance of MVR heat pump increase is not obvious.Design the mass capacity of 50 kg/h sludge hollow blade of MVR heat pump drying system.choose JY-003 hollow blade dryer and roots compressors, designed the Screw feeder, auxiliary device for the selection. And MVR heat pump drying system for the installation and debugging.the experiment system for constant speed stage of sludge intermittent drying experiment was studied. the results show that the initial moisture content is 75%, the quality of 120 kg, hot shaft speed is 11.3 r/min, under the drying pressure of 80 kPa, the compression ratio from 1.5 to 1.9, the COP from 5.3 to 3.9, the SMER from 6.9 to 5.2 kg/(kW·h), refer to the current steam electricity price ratio, In constant speed, using the MVR drying heat pump system, has the practical value. In constant speed of dry sludge, reduce the drying stress, decrease the compression ratio, select the appropriate hot shaft speed is beneficial to improve the efficiency of the operation of the system; Put forward the optimization of MVR heat pump drying system mainly has two directions: one is to improve the efficiency of the compressor, the second is to enhance the performance of heat transfer in the dryer. The experiment result show that apply MVR technology in drying has a certain theoretical significance and engineering application value.