Design And Performance Research Of The Jacketed Mechanical Vapor Recompression Heat Pump Evaporation System

The technology of Mechanical Vapor Recompression heat pump is a currently the most efficient and environmentally friendly energy-saving technology in the process of evaporation. The jacketed mechanical vapor recompression heat pump evaporation system driven by single screw vapor compressor was designed,manufactured, assembled to possibile approach the actual effect of the evaporation system, to be used for the industrial production as soon as possible, at the same time,to lay the experimental foundation for the subsequent large-scale energy-saving recasting of the chemical enterprise, and was carried out the industrial application research. Through the research on the system’s theoretical analysis, equipment design and analysis, running experiments and comprehensive performance analysis,energy-saving economy analysis and the demonstrative application, etc. getting the following conclusions:( 1) The maximum temperature difference reached 26.54 ℃, the maximum compression ratio reached 2.43, the maximum evaporation capacity reached316.56kg/h, the maximum coefficient of heat transfer reached 1257.8W·m-2·℃-1, the maximum coefficient of performance reached 9.73, the maximum specific moisture extraction rate reached 15.84kg·kw-1·h-1, the maximum adiabatic efficiency reached0.74, the maximum volumetric efficiency reached 0.81. All showed that the newly developed single screw vapor compressor had excellent performance.( 2) The performance of the system was much better than that of other conditions with lower frequency when single screw compressor was running at the frequency of 50 Hz, and it was unnecessary to compensate external steam. The system should be maintained at a high frequency operation to adapt to the demands of different workload.(3)The most appropriate range of evaporating pressure was from 65 kPa to85 kPa when single evaporating kettle was running at the frequency of 50 Hz.Coefficient of performance, specific moisture extraction rate, adiabatic efficiency and volumetric efficiency had a maximum within this range. The system that there was the best operating condition was the most energy-saving.(4)Each of performance evaluation targets of the system was influenced by operational and structural parameters like the frequency of compressor operation,evaporating pressure(evaporating temperature) and heat transfer area.(5)Double evaporating kettle synchronously running was better than single evaporating kettle operation, continuously feeding conditions was better than intermittent feeding condition.(6)The maximum evaporation capacity of the system was greater than 250 kg/h.The maximum economic benefits of the system’s operation cost energy-saving reached 80%. It fully met the research project’s rigid targets for the proposed system equipment, synchronously indicated that the system could be applied to the processes of actually industrial evaporation.