中文摘要：

采用锅炉正平衡计算方法，辅以反平衡计算法，对某自备电站75t／h中压三气混烧燃气锅炉进行了热力计算．根据燃气锅炉燃料特性，结合现场检测锅炉热工参数，分析了影响燃气锅炉热效率的因素，计算了排烟温度及散热量损失所占比例，通过分析，找出了最佳运行空气过剩系数，以提供合理的供风量，从而节约能源，减少排烟量，减少热损失，提高锅炉燃烧效率．

英文摘要：

In this paper, the thermal calculation is been done based on the 75t/h medium-pressure gas boiler which combines the natural gas, BFG and LDG in the electricity station supplied by some company utilizing the boiler balance calculation and alo anti-balance calculation supplement method. And it analyzes the factors to influence the thermal efficiency of gas boiler and caculates the the temputure of emission smoke and the proportion of heat loss according to the characteristics of gas boiler and the boiler thermal parameter tested in the site; Through analysis the surplus air confieient in the exit of exellent operations, this paper pays attention to offer the reasonable amount of wind, saving energy, reducing emission and heat loss and to improve the burning effiency of boiler by the technologies, equipments and skills.