煤化工一氧化碳变换单元低位热能利用初探

Preliminary discuss on low-level energy utilization of CO shift unit in coal chemical industry

能源匮乏、环境污染已成为世界范围的问题,节能降耗、提高能源的综合利用率,是解决能源问题的重要有效途径。煤制甲醇一氧化碳变换单元原设计根据温度梯度,回收热量副产4.1MPa、1.1MPa和0.46MPa蒸汽,但在实际生产过程中,夏季1.1MPa蒸汽富裕,只能将多余的蒸汽现场放空,能量利用不合理,损失大。本文对低位能量利用方面的技术进行介绍和讨论,包括热交换技术、热泵技术、余热制冷技术和发电技术。模拟计算了使用1.1MPa过热蒸汽进行余热发电的可行性和经济效益,并且提出了将煤化工装置产生的低位蒸汽用于废水多效蒸发,提高废热回收效率,同时减少装置水耗。

Energy shortage and environmental pollution have become worldwide problems. Energy conservation, consumption reduction and comprehensive utilization of energy are important and effective ways to solve energy problems. According to the temperature gradient, the heats were recovered to produce 4.1 MPa, 1.1 MPa and 0.46 MP steam by-products in the original design of carbon monoxide shift unit in the coal-to-methanol plant. But in the actual operation, 1.1 MPa steam was rich in summer and was vented to the environment, which was not reasonable and wasteful in the utilization of energy. This paper introduces and discusses the technologies of low-level energy utilization, including heat exchange, heat pump, waste heat refrigeration and power generation.The feasibility and economic benefit of using the waste 1.1 MPa superheated steam for power generation are simulated and calculated.It is also suggested that low-level steam from coal chemical plants be used for multi-effect evaporation of wastewater to improve the efficiency of waste heat recovery and reduce the water consumption of the plants.