摘要
Abstract
In flue gas waste heat recovery system which contains the air heater function ,It also involves changes to the boiler side thermal efficiency evaluation at the same time in calculating thermal heat efficiency gain of steam turbine side because of the boiler exhaust temperature changing. According to the traditional concept, the boiler exhaust gas temperature increase give rise to the heat exhaust gas loss, which will enable the boiler efficiency decline and coal consumption increase. But the problem whether boiler exhaust gas temperature increase is certainly caused by boiler efficiency decrease and coal consumption increase is worth discussing when the air preheater inlet air temperature improving. According to the heat balance principle, the relationship between exhaust gas temperature and boiler efficiency and coal consumption is analysised, the results show that: there are two different kinds of expression patterns is existed between the effect of flue gas temperature and the boiler efficiency. When the exhaust gas temperature increased which caused by air preheater inlet air temperature improve, the boiler calculation efficiency which is taking the coal calorific value as the base will increase, which is taking the input heat as the base will reduce. But the effect of these two kinds of expression pattern to the final coal consumption change is the same. Two different efficiency concepts must be distinguished in application. In practice, boiler efficiency mode based on coal calorific value is first recommended. In addition, the ratio between the exhaust temperature increase and the inlet air temperature increase, but the exhaust temperature only ,to assess the change of exhaust heat loss, boiler efficiency and coal consumption. Two different concepts should be distinguished also between“air preheater exhaust temperature” and“boilerunit exhaust temperature” in gas waste heat recovery system.关键词
排烟温度/排烟热损失/锅炉效率/锅炉煤耗/空预器/等效排烟温度Key words
exhaust gas temperature/heat loss due to exhaust gas/boiler efficiency/coal consumption of boiler/air temperature increase/air preheater/equivalent exhaust temperature分类
信息技术与安全科学
