The impact of cogeneration plant and a storage tank in a district heating system

Abstract

The goal of the study is to investigate the thermal behavior and the benefits of a cogeneration system based on two gas fired engines and of a thermal storage tank in a biomass based district heating system situated in Romania. The investigation is based on an hourly analytical model of all the district heating components: biomass boiler, natural gas cogeneration engines, storage tank and consumers. The climatic data of the location are used as input in the model. The gas cogeneration engines coupled with the heat storage tank increase the flexibility of the system and allow the production of electricity even in periods with little or no heat demand. The analytical modelling of the storage tank considering the water stratification allows the correct sizing of the storage tank, in the planning stage of the project. The total yearly heat production is divided between 81.54 % produced by the proposed cogeneration plant and 18.46 % produced by the existing biomass boiler.