基于管网特性的集中供热系统动态热力工况研究

发布时间：2018-08-26 19:59

【摘要】：由于集中供热具有供热效率高,环境污染物排放易于集中处理等优点,在国家的高度重视和大力支持下,我国的集中供热事业在近年来取得了迅速的发展。但由于我国的供热事业起点较低且起步较晚,供热系统的能源利用效率仍然较低。面对日益严峻的全球性能源制约和环境问题,集中供热系统的节能、高效运行成为我国供热行业必须重视的问题。为了在满足热用户舒适度的前提下实现供热系统的节能运行,就需要使系统的供热量随时与热用户的需热量保持一致。因此,对供热系统的动态热力工况进行分析就显得非常重要。本文首先建立考虑管段温度衰减度的集中供热系统热力工况数学计算模型。改进了常规的供热管网模型,在热用户的进出口处增加节点,建立了考虑管段温度衰减的热力工况网络拓扑结构;分析了直接连接供热系统和间接连接供热系统的热力特性,建立了直接连接供热系统热力工况计算模型和间接连接供热系统热力工况计算模型。基于管网的动态特性建立了管段温度衰减度的计算模型,并用实际供热系统的运行监测数据对模型进行验证,表明了理论模型建立的正确性。利用建立的供热系统热力工况计算模型对供热系统进行热力工况分析。研究不同运行调节方式下,管段温度衰减度对热用户室内温度的影响规律。通过分析可以看出:在每个供暖阶段内,随着室外温度的升高,管段温度衰减对热用户室内温度的影响不断减弱;集中供热调节时应考虑管网温度的衰减,在提高热源出口供水温度保证各热用户都能达到供热要求的前提下,再根据热用户的过热情况对热用户处的流量进行局部调节,以减少用户的热力不平衡；
[Abstract]:Due to the advantages of high heating efficiency and easy centralized treatment of environmental pollutants, the central heating industry in China has been developing rapidly in recent years with the great attention and support of our country. However, the energy efficiency of the heating system is still low because of the lower starting point and late start of the heating industry in China. In the face of increasingly severe global energy constraints and environmental problems, the energy saving and efficient operation of central heating system has become a problem that our heating industry must pay attention to. In order to realize the energy-saving operation of the heating system under the premise of satisfying the comfort of the heat users, it is necessary to keep the heat supply of the system consistent with that of the heat users at any time. Therefore, it is very important to analyze the dynamic thermal condition of heating system. In this paper, a mathematical model of central heating system is established considering the temperature attenuation of pipe section. The conventional heat supply network model is improved, the nodes are added at the inlet and outlet of the heat user, the topology of the network considering the temperature attenuation of the pipe section is established, and the thermodynamic characteristics of the direct and indirect connection heating system are analyzed. The calculation model of direct connection heating system and indirect connection heating system is established. Based on the dynamic characteristics of the pipe network, the calculation model of the temperature attenuation of the pipe section is established, and the model is verified by the operation monitoring data of the actual heating system, which shows the correctness of the establishment of the theoretical model. The thermal working conditions of the heating system are analyzed by using the established heat supply system calculation model. The influence of pipe temperature attenuation on the indoor temperature of hot users was studied under different operation regulation modes. Through analysis, we can see that in each heating stage, with the increase of outdoor temperature, the influence of pipe section temperature attenuation on the indoor temperature of thermal users is weakened, and the attenuation of pipe network temperature should be considered in central heating regulation. On the premise of raising the water supply temperature at the outlet of the heat source to ensure that all the heat users can meet the requirements of heating, the flow rate of the heat user is locally adjusted according to the overheating condition of the heat user, so as to reduce the thermal imbalance of the user.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU995

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