燃煤电厂余热利用CO_2膨胀压缩一体机设计研究

Design of CO_2 Expansion-compression-integrated Machine for Waste Heat Utilization in Coal-fired Power Plants

指出了燃煤电厂煤炭资源的平均利用率不足50%,有50%以上的能量以各种热损失的形式排入环境。为了充分利用燃煤电厂排放的余热,设计完成了一种CO_2膨胀压缩一体机热泵系统,其具有高工作压力、大压差的工作特性,解决了CO_2的跨临界循环中节流损失大的问题,提高其循环效率;系统由液压提供动力,能实现无极调速及设备积木式容量扩展;压缩膨胀双冲程直线对置运行,提高了设备的运行效率;另外,还搭建了试验台,对设备运行的可行性进行了验证。CO_2膨胀压缩一体机的使用将对燃煤电厂的低温余热回收,提高运行效率提供一种方法。

The average utilization rate of coal resources in coal-fired power plants is less than 50%, and more than half of the energy is emitted into the environment. In order to make full use of waste heat of coal-fired power plant emission, a CO2 expansion-compression-integrated heat pump is designed, which has high working pressure and large pressure drop, so that the problem of large throttling losses in the transcritical cycle of CO2 was solved and the circulation efficiency was thus improved. The system is powered by hydraulic power, which can realize stepless speed adjustment and the block-type expansion of equipment capacity, so that the operating efficiency of the equipment can be improved. In addition, a test stand was built to verify the feasibility of equipment operation. The use of the CO2 expansion-compression-integrated machine will provide a method for recovering low-temperature waste heat from coal-fired power plants and improving operating efficiency.