具有吸收式热泵供热的热电联产机组调峰特性分析

发布时间：2018-01-28 09:27

本文关键词： 热电联产热泵调峰吸收式供热　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：利用吸收式热泵回收热电排汽余热用于供热,具有节能、环保、经济等效益突出的特点,因此被广泛应用于热电联产行业,提高了能源利用效率,扩大了机组的供热能力。经济的发展转变了我国用电结构和用电需求,电力系统呈现出峰谷差日益扩大,调峰需求显著增多的特点。热电联产机组参与调峰,是减小电网峰谷差和解决风电消纳的重要途径,具有吸收式热泵供热的热电联产机组调峰已经成为当前亟需解决的问题。本文以已投运的具有吸收式热泵供热的热电联产机组为研究对象,旨在获取该类型机组的调峰能力,以Ebsilon软件构建热力学模型仿真机组的运行工况,探究热电调峰对机组供热性能的影响,确定机组供热期间最大调峰能力的计算原则,绘制具有吸收式热泵供热的热电联产机组的调峰运行工况图,拟合机组调峰能力计算公式,具体内容如下:(1)分析溴化锂吸收式热泵的热力过程,设计并构建基于效率因子法和基于实际循环的两种模型,与现场调试数据进行对比,验证基于两种吸收式热泵的模型的计算精度,确定两种模型的应用场合和选用依据。(2)构建基于Ebsilon的汽轮机变工况仿真模型,提出基于滑压控制、汽轮机级组效率、和低压缸排汽损失的修正方法,提高模型精度,对比机组不同负荷的设计数据和模型模拟结果,验证模型的精度。(3)借助模型分析了外界因素变动(循环水、抽汽压力和热网水温)对吸收式热泵制热系数COP的影响。模拟汽轮机变工况引起的相关供热参数的变动,为系统实际调峰期间获得稳定的供热负荷控制提供了数据支撑。(4)基于热电联产机组调峰限制因素,建立热电联产机组最大负荷和最小负荷的计算原则。借助仿真模型绘制出具有吸收式热泵供热的热电联产的调峰运行工况图,拟合出最大调峰功率线和最小调峰功率线,并通过最小二乘法对热电负荷进行拟合,得到热电联产机组调峰运行限值,为热电负荷调度和电网调峰指导提供理论依据。考虑到机组调峰期间,热泵COP易受众多因素影响的特点,分析了 COP变动对机组调峰能力的影响,得到以下结论:吸收式热泵供热耦合热电联产影响机组调峰性能,当机组供热负荷较低时,热泵的运行会降低机组的调峰能力;当机组负荷增长到一定阶段,热泵的运行能显著提高机组的调峰能力,COP达到设计值时,最大供热负荷下,采用热泵供热系统调峰能力比传统供热方式提高91%,且其对机组电力调峰能力的影响受热泵制热系数COP的影响,COP越大,热泵供热对热电联产机组调峰能力提升越明显。
[Abstract]:Absorption heat pump is used to recover waste heat from heat and electricity exhaust steam for heating, which has the advantages of energy saving, environmental protection, economy and so on, so it is widely used in the cogeneration industry of heat and power, and improves the efficiency of energy utilization. The economic development has changed the power consumption structure and demand in our country. The power system presents the characteristics of increasing peak and valley difference and increasing peak demand. The cogeneration units participate in peak-shaving. It is an important way to reduce the peak and valley difference and solve the wind power consumption. The peak-shaving problem of heat and power cogeneration units with absorption heat pump heating has become a problem that needs to be solved at present. In this paper, the heat and power cogeneration units with absorption heat pump heating have been put into operation as the research object. In order to obtain the peak-shaving ability of this type of units, a thermodynamic model was constructed with Ebsilon software to simulate the operating conditions of the units, and the influence of thermal power peak-shaving on the heating performance of the units was explored. Determine the calculation principle of maximum peak-shaving capacity during the heating period of the unit, draw the peak-shaving operation diagram of the cogeneration unit with absorption heat pump, and fit the calculation formula of the peak-shaving capacity of the unit. The main contents are as follows: 1) the thermodynamic process of libr absorption heat pump is analyzed, and two models based on efficiency factor method and actual cycle are designed and constructed, and compared with the field debugging data. Verify the calculation accuracy of the two absorption heat pump models, determine the application of the two models and select the basis... 2) to build the turbine simulation model based on Ebsilon. Based on sliding pressure control, turbine stage efficiency, and low-pressure cylinder exhaust steam loss correction method is proposed to improve the model accuracy, and to compare the design data and model simulation results of different load units. To verify the accuracy of the model, the variation of external factors (circulating water) is analyzed with the help of the model. The influence of extraction pressure and heat network water temperature on the heating coefficient COP of absorption heat pump is simulated. It provides data support for obtaining stable heat supply load control during the actual peak-shaving period of the system) based on the limiting factors of peak-shaving of cogeneration units. The calculation principle of maximum load and minimum load of cogeneration unit is established, and the peak shaving operation diagram of heat and power cogeneration with absorption heat pump is drawn with the aid of simulation model. The maximum peak-shaving power line and the minimum peak-shaving power line are fitted and the thermoelectric load is fitted by the least square method. This paper provides a theoretical basis for thermoelectric load dispatching and peak-shaving guidance of power grid. Considering the characteristics that heat pump COP is easy to be affected by many factors during peak shaving, this paper analyzes the influence of COP variation on the peak-shaving ability of generating units. The following conclusions are obtained: the combined heating and electricity cogeneration of absorption heat pump affects the peak-shaving performance of the unit, and when the heat supply load of the unit is low, the operation of the heat pump will reduce the peak-shaving ability of the unit; When the load of the unit increases to a certain stage, the operation of the heat pump can significantly improve the peak-shaving capacity of the unit and the cop reaches the design value, under the maximum heating load. The peak-shaving capacity of heat pump heating system is 91% higher than that of the traditional heating mode, and the influence of heat pump heating coefficient (COP) on the power peak shaving capacity of the unit is greater than that of the traditional heating mode. Heat pump heating on the cogeneration unit peak-regulation capacity to enhance the more obvious.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM621

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