蒸汽再压缩技术研究现状与发展趋势

干燥、浓缩等高能耗工序在消耗大量高压蒸汽的同时产生大量乏汽,这些乏汽因温度、压力过低无法被直接利用而排放,造成大量蒸汽潜热浪费。本文对可用来充分回收乏汽汽化潜热、提高系统热效率的蒸汽再压缩技术进行了介绍。经过蒸汽再压缩系统压缩后,乏汽的压力与温度同时被升高重返生产工艺,实现乏汽汽化潜热充分回收利用。首先对生产过程中不同蒸发方式的特点和不足进行了比较,如单效蒸发、多效蒸发及多效闪蒸等蒸汽利用技术;然后分析了实现乏汽升压的不同方法包括热力蒸汽升压技术和机械式蒸汽升压技术的应用现状及优缺点。对机械蒸汽再压缩（MVR）技术进行了详细介绍,在比较离心式蒸汽压缩、罗茨式蒸汽压缩和螺杆式蒸汽再压缩技术的基础上,详细分析了螺杆式蒸汽再压缩技术在蒸汽再压缩领域的应用及发展趋势。最后,简要介绍了蒸汽压缩技术在制冷、热泵领域的应用前景及蒸汽再压缩技术在干燥与浓缩等领域的应用概况,着重介绍了MVR技术在浓缩、干燥、海水淡化等领域的应用情况及节能改造措施。指出了未来蒸汽再压缩技术的发展趋势。

Overview and Development Tendency of Steam Recompression

High energy consumption processes such as drying and concentration consume a large amount of high pressure steam and generate a lot of exhaust steam, which can’t be directly used due to too low temperature and pressure, resulting in severe waste of latent heat. In this paper, the steam recompression technology was introduced, which can be used to recover the latent heat of exhaust steam and improve the system efficiency. After being compressed by the steam recompression system, the pressure and temperature of the exhaust steam were increased, and the latent heat of the exhaust steam was fully recovered and utilized. The characteristics and disadvantages of different evaporation methods such as single-effect evaporation, multi-effect evaporation and multi-effect flash evaporation in the production process were compared. Then, the application status, advantages and disadvantages of different exhaust steam recompression methods including thermal steam recompression and mechanical steam recompression technologies were analyzed. The mechanical vapor recompression (MVR) technology was introduced in detail. Based on the comparison of centrifugal compressor, roots compressor and screw compressor, the application and development trend of screw compressor in the field of steam recompression were described. Finally, the application prospect of steam compression in refrigeration and heat pump, and the application of steam recompression in drying and concentration were briefly introduced, and the application of MVR in concentration, drying, seawater desalination as well as energy saving measures were emphatically introduced. The development trend of steam recompression technology in the future was pointed out.