基于变工况分析的供热机组负荷特性研究

Study of the Load Characteristics of a Heat-supply Unit Based on an Analysis of Its Off-design Operating Conditions

目前,电厂与电力调度部门在确定供热机组的热电负荷调度范围问题上普遍存在争议,为此根据供热机组的热力参数和机组特性,以变工况热力计算为依据,产生机组的热电负荷调度关系曲线。通过与由机组工况图所产生的热电关系曲线对比可以发现,热力计算所得到的热电关系曲线具有足够的精度。而且,通过热力计算的方法,可以更好地将其它限制机组负荷调度的因素考虑进去,使得调度范围更加合理。同时,这种方法可以有效的预测抽汽参数的改变对机组负荷调度的影响,通过对比发现,对于供热抽汽压力较高的机组,适度的降低其抽汽压力可以提高机组的电负荷调度范围。该方法可以为电厂与调度部门的负荷调度问题提供合理的解决方案。

At present,there exist universally disputes between power plants and the electric power dispatchment departments concerning the matter how to determine the dispatchment scope of the heat-power load for a heat-supply unit.On the basis of the thermal parameters and characteristics of the heat-supply unit together with its off-design operating condition thermal calculation results,curves showing the relationship of the heat-power load dispatchment were obtained.Through a comparison with the curves showing the heat-power relationship obtained by using the chart of the operating conditions of the unit,it can be found that the curves obtained from the thermal calculation have an enough calculation precision.Moreover,through adopting the thermal calculation method,other factors,which limit the load dispatchment of the unit,can be taken into account properly,thus making the dispatchment scope more rational and reasonable.At the same time,the method in question can effectively predict the influence of a change in the steam extraction parameters on the load dispatchment of the unit.Through a comparison,it can be found that for a unit with a relatively high heat supply steam extraction pressure,to properly reduce the steam extraction pressure can enhance the power dispatchment scope of the unit.The method under discussion can offer a sound and correct solution to the load dispatchment problem between a power plant and its heat-power dispatchment department.