Off-design simulation and mathematical modeling of small-scale CHP plants at part loads
Off-design simulation and mathematical modeling of small-scale CHP plants at part loads
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DOI：
10.1016/j.applthermaleng.2004.08.009
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发表时间：
2005-06
影响因子：
6.4
通讯作者：
Tuula Savola;I. Keppo
中科院分区：
文献类型：
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作者：
Tuula Savola;I. Keppo
在这项工作中，热电联产（CHP）厂在部分负荷的数学模型的基础上开发的非设计模拟的四个现有的小规模（1 - 20 MWe）热电联产厂。电力市场的放松管制和生物燃料的区域供应为小型热电联产厂提供了新的机会。这些设备通常在部分负荷条件下长时间运行，这使得了解它们的部分负荷行为非常重要。这里提出的模拟结果表明，虽然热电联产厂的部分负荷发电可以相当准确地描述与一条线，有一个小的非线性减少，在电力生产的区域热负荷降低。根据模拟结果，建立了描述发电量及其非线性变化随区域热负荷和供热水温变化的二、三线回归模型。根据与单线和双线回归模型的比较，三线模型最准确地描述了部分负荷下的模拟CHP过程（即，R2值最大）。开发的模型可以用于，例如，更详细地优化一个带有小型热电联产厂的区域供热网络。在评估热电联产厂的年产量时，热持续时间曲线的准确性可能与发电模型的准确性一样对结果产生很大影响。
In this work a mathematical model of combined heat and power (CHP) plants at part loads was developed on the basis of off-design simulations of four existing small-scale (1–20MWe) CHP plants. The deregulation of the electricity market and the regional availability of biofuels have given new opportunities for small-scale CHP plants. These plants are often operated for long time periods at part load conditions, which makes the knowledge of their part load behaviour very important. The simulation results presented here showed that although the part load power production of a CHP plant can be described quite accurately with a single line, there is a small nonlinear reduction in the power production as the district heat load decreases. Based on the simulation results two and three line regression models describing the electricity production and its nonlinear changes as a function of the district heat load and the outgoing district heating water temperature were developed. According to a comparison with a single and a two line regression model, the three line model describes the simulated CHP processes at part loads most accurately (i.e., has the highest R2value). The developed models can be used, e.g., for more detailed optimisation of a district heating network with a small-scale CHP plant. When evaluating the annual production of the CHP plant the accuracy of the heat duration curve may have as high influence on the results as the accuracy of the power production model.