Pirouti, Marouf, Bagdanavicius, Audrius, Wu, Jianzhong ORCID: https://orcid.org/0000-0001-7928-3602, Jenkins, Nicholas ORCID: https://orcid.org/0000-0003-3082-6260 and Ekanayake, Janaka ORCID: https://orcid.org/0000-0003-0362-3767 2012. Optimal operation of a district heating system. Presented at: 7th Conference On Sustainable Development Of Energy, Water And Environment Systems, Ohrid, Republic of Macedonia, 1-7 July 2012. |
Abstract
Heat loss in pipes and pump electrical energy consumption are unavoidable during the operation of a district heating (DH) system. In order to reduce total operating costs and improve energy efficiency appropriate operating strategy should be chosen. This study is aimed at optimising the supply water temperature and mass flow rate in a DH system, depending on the heating load variations. The minimisation of operating costs of DH system with different heat sources was conducted. Two different design cases of a DH pipe network based upon of a real project redevelopment in Wales, UK, were considered. First, the DH pipe network was designed based on a low pressure loss (100 Pa/m). It means that pipes with large diameters and small size pump were chosen. Second, the DH pipe network was re-designed using a larger pressure drop (1200 Pa/m). In this case smaller diameter pipes and larger size pump were selected. An optimisation model was developed using FICOTM Xpress optimisation tool. Hydraulic and thermal calculations were validated using commercial software PSS SINCAL. Three cases with different heat sources connected to the DH network were investigated. In the first case it was assumed that the fuel cost was negligible. In the second case, water boiler was used. In the third case combined heat and power (CHP) connected to the DH network was considered. The optimisation of annual supply water temperature and mass flow rate was achieved by minimising annual operating costs. Heat loss and pump energy consumption were calculated. Results show that optimum flow and supply temperature profile over the year are different when different types of heat sources and different designs of the DH pipe network are used. The difference is particularly substantial when a CHP connected to the DH network, is used. It is observed that it is an advantage to reduce system supply temperature and increase flow rate more compared to the other heat sources connected to the DH network. In order to increase CHP electricity revenue and reduce heat loss cost when a back pressure steam turbine CHP is used .
Item Type: | Conference or Workshop Item (Keynote) |
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Date Type: | Completion |
Status: | Published |
Schools: | Engineering |
Subjects: | T Technology > TD Environmental technology. Sanitary engineering |
Related URLs: | |
Last Modified: | 09 Nov 2022 09:11 |
URI: | https://orca.cardiff.ac.uk/id/eprint/44486 |
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