Abstract：

Designers should pay attention to the effect of high altitude on the boiler combustion efficiency, and check the boiler capacity at the high altitude area. Taking a district heating design in Xining as an example, analyses main reasons that indoor temperature cannot reach the requirement, and concludes that the designers do not consider the significant impact of atmospheric conditions on the combustion gas at the high altitude area, and still select the heat source  according to the design method in the plain region, so the output of heat source is insufficient. Based on the local atmospheric pressure, oxygen content and other parameters, with the theoretical analysis method, analyses the heat loss due to exhaust gas and gas incomplete combustion at the high altitude area, and obtains the analysis values of the boiler thermal efficiency.