基于高温热泵的电厂循环水余热回收系统研究

Waste Heat Recovery System of Circulating Water in Power Plant Based on High Temperature Heat Pump

针对我国火电厂效率低下,导致产生大量余热由冷却塔直接排入环境,从而造成热污染问题。笔者以600 MW机组电厂为例,提出一种基于高温热泵回收余热并且提高余热品位用于加热送风的系统;并与燃煤锅炉、燃气锅炉等传统供热方式对比,从经济效益与减排方面进行分析比较。分析结果表明,受当地电价和天然气价格影响,燃气锅炉费用最高,高温热泵的余热回收系统运行费用仅次于燃气锅炉,且每年可减少1 137.4 t的CO_(2)以及其他污染物排放。该系统不仅具有经济性且节能减排,符合国家“双碳”政策导向。

In view of the low efficiency of thermal power plants in China, a large amount of waste heat is directly discharged into the environment from the cooling tower, resulting in thermal pollution. Taking a 600 MW unit power plant as an example, a system based on high temperature heat pump to recover waste heat and improve waste heat grade for heating air supply is proposed. Compared with traditional heating methods such as coalfired boilers and gas boilers, the economic benefits and emission reduction are analyzed and compared. The analysis results show that the cost of gas boiler is the highest due to the influence of local electricity price and natural gas price. The operation cost of waste heat recovery system of high temperature heat pump is second only to that of gas boiler, and it can reduce 1137.4 t of CO_(2) and other pollutant emissions per year. The system is not only economical but also energy saving and emission reduction, which is in line with the national dual carbon policy orientation.