直接空冷高背压供热机组冷端优化与系统节能研究

发布时间：2018-08-30 16:58

【摘要】：热和电是能源互联网消费终端中的两种重要产品,热电联产机组可同时满足热和电的供应需求,传统的中间抽汽式供热机组由于抽汽品质仍然较高,依然存在较大的?损失,空冷高背压供热模式则是利用排汽作为热源,更好得符合了“温度对口,梯级利用”的总能系统原则,近些年得到大力发展。与传统抽汽供热方式相比,直接空冷高背压供热机组具有显著的冷端运行复杂性,当外界热负荷和电负荷发生变化时,机组弹性运行对应的参数状态、限制边界及能耗特性均不同于凝汽式空冷机组或背压式供热机组。对于空冷供热机组,系统供热特性与环境温度存在很强的依变关系。一方面,环境温度变化时刻影响热负荷供应需求;同时,空冷岛的冷却效果也受到环境风温度和迎面风速等因素影响。作为热源的供热凝汽器和承担剩余冷却负荷任务的空冷岛作为机组冷端的两大部分,在变工况运行时也存在着复杂的耦合关系。考虑到冬季供热的重要性,大部分机组均采取“以热定电”的运行方式以满足热负荷实时变化需求;空冷岛在冬季也有着严格的阻塞背压和防冻流量要求,因此,研究直接空冷高背压供热机组的梯级供热特性,以及不同工况下空冷系统与供热系统的协同运行优化至关重要。在新能源装机比例不断上升的新常态下,热电机组如何应对能源供给侧改革的要求值得关注。基于EES和Ebsilon平台建立了直接空冷高背压供热机组的传热和供热特性模型,针对不同的热负荷和电负荷状况,探讨热网采用质调节,量调节,质-量并行调节时机组冷端参数的变化和弹性运行的边界,以汽轮机背压为特征参数确定机组在特定负荷下不同运行工况的能耗情况,以西北地区某省级电网的用电负荷,风电负荷及热负荷为案例,探讨供热期内典型温度范围内的高背压供热机组的弹性运行能力,得到了热电弹性运行对于风力发电波动的平抑效果,为能源互联网供给侧改革和区域能源规划提供参考。
[Abstract]:Heat and electricity are two important products in the energy internet consumption terminal. The heat and electricity cogeneration unit can meet the supply demand of heat and electricity at the same time. Loss, air cooling high back pressure heating mode is to use exhaust steam as heat source, better in line with the "temperature matching, cascade utilization" of the total energy system principle, has been vigorously developed in recent years. Compared with the traditional extraction heating mode, the direct air-cooled high backpressure heating unit has remarkable cold end operation complexity. When the external heat load and electric load change, the corresponding parameter state of the unit's elastic operation is obtained. The limited boundary and energy consumption characteristics are different from condensed air cooling units or backpressure heat supply units. For air-cooled heating units, there is a strong dependent relationship between system heating characteristics and ambient temperature. On the one hand, the change of ambient temperature affects the demand of heat load supply, and the cooling effect of air-cooled island is also affected by the factors such as the ambient wind temperature and the direct wind speed. The heating condenser as a heat source and the air-cooled island which takes on the task of residual cooling load as the two parts of the unit cold end also have complex coupling relations in the operation of variable working conditions. Considering the importance of heating in winter, most units adopt the operation mode of "heating with heat" to meet the demand of real-time change of heat load. The air-cooled island also has strict requirements of blocking back pressure and anti-freezing flow in winter, so, It is very important to study the cascade heating characteristics of direct air cooling high back pressure heating units and to optimize the coordinated operation of air cooling system and heating system under different working conditions. Under the new normal condition with the increasing proportion of new energy installed, how to deal with the demand of energy supply side reform is worthy of attention. Based on the platform of EES and Ebsilon, the heat transfer and heating characteristic model of direct air cooling high back pressure heating unit is established. According to the different heat load and electric load, the heat network adopts quality regulation and quantity regulation. The change of unit cold end parameters and the boundary of elastic operation under the condition of parallel quality and quantity regulation. The energy consumption of the unit under different operating conditions under specific load is determined by the characteristic parameters of steam turbine back pressure, and the power load of a provincial power network in Northwest China is used. Wind power load and heat load are taken as examples to discuss the elastic operation ability of high back pressure heat supply units in the typical temperature range of heat supply period, and the effect of thermoelectric elastic operation on the fluctuation of wind power generation is obtained. For the energy supply side of the Internet reform and regional energy planning to provide a reference.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM621

【参考文献】