Investigation of solar accommodation via storage configuration in district heating system based on granularity analysis

Abstract

In the pursuit of achieving carbon neutrality, it is essential to advance the broad accommodation of renewable energy for the realization of a low-carbon district heating system (DHS). The heat storage configuration serves as an effective assurance for facilitating the accommodation of renewable energy in DHS. This paper analyzes the impact of heat storage configuration on the accommodation of solar energy in DHS, employing a granularity analysis method. This study proposes an optimization method for determining the maximum solar energy accommodation rate in solar-assisted DHSs using the granularity analysis method. Furthermore, this study optimizes the heat storage capacity configuration to facilitate varying ratios of solar energy accommodation. Finally, a technical-economic analysis of the solar-assisted DHS is performed in the context of rising energy cost. The case study reveals that greater granularity leads to a higher solar energy accommodation rate. Specifically, when the granularity increases from 0.43% to 22.22%, the solar energy accommodation rate increases by 8.01%. Moreover, the heat storage capacity configuration increases with the increase of the solar energy accommodation rate, while the heat storage capacity required to accommodate per unit of solar energy decreases. Additionally, as the granularity increases from 0.43% to 22.22%, the heat storage capacity configuration under the same solar energy accommodation ratio increases gradually. This study explores the potential of granularity-based heat storage configuration optimization in promoting solar energy accommodation and achieving the economy of DHS, which is of great significance for the decarbonization of DHS.