Steam is an important medium for energy transmission in the district energy system. When there are many consumers with different temperature and load demand, an optimized scheme for steam production and supply for the central energy station is of great significance to save the total cost of the steam system. The key problem is the selection of the number of steam level. With the increasing number of steam levels, the energy demand and supply can be matched more suitably, and more electricity can be generated. At the same time, the investment of steam pipeline network increases. In this paper, this trade-off is solved by a mathematical programming model. The objective function is to minimize the total cost of the steam system of district energy systems. The physical properties of steam are formulated by second-order polynomials, so the structure and parameter optimization of the multi-level steam system can be conducted simultaneously. A case study has proved that the change of the number of steam level have an impact on various costs. In this case, the optimal number of steam level is 3, and the total annual cost is 26.7 k$ lower than the suboptimal option with 4 levels of steam.
|Publication||Impact Factor journals|
|Affiliation of speaker||China University of Petroleum|