Abstract
The modelling of uncoupled fluid flow and heat transfer problems of a district heating network using the finite element method (FEM) is presented. Since the standard thermo-hydraulic pipe elements cannot be directly used for modelling insulation, the main attention was paid to discretisation of multilayered structure of pipes and surrounding by one-dimensional thermal elements. In addition, validity of the finite element method was verified numerically by solving fluid flow and heat transfer problems in district heating pipelines. Verification analysis involves standard single pipe problems and simulation of fragment of district heating in Vilnius. Pressure and temperature results obtained by finite element method are compared with those by other approaches.
Highlights
District heating distribution systems require careful design and construction to ensure the lowest maintenance and longest life
The district heating systems can be divided into three parts (Fig 1): 1) plant, 2) the DH distribution or transmissions network and 3) the consumers where each individual consumer is defined as a heat exchanger and all installations on the secondary side of each substation
The model applied for simulation in TERMIS software has the simplification in determination of heat losses, and as a result of this simplification the overall heat transfer coefficient is to be chosen for each pipe from pipe specifications, such as [27]
Summary
District heating distribution systems require careful design and construction to ensure the lowest maintenance and longest life. The solution of heat transfer problem in thermo-hydraulie flow analysis contains difficulties due to the multilayered structure of the pipeline and due to different heat transfer modes having state-dependent characteristics Some of these factors are neglected in engineering practice for simplicity reasons. The finite element method (FEM) is a powerful tool for fluid flow and heat transfer analysis, and it has been mostly applied for solving two- or three-dimensional problems. For solution of hydraulic problem in fluid network, FEM was applied in [16], while an in-house FE code was developed in [17] by approximation flow in pipes with lD finite elements hocked together. Validity of the finite element method is verified by solving fluid flow and heat transfer problems in district heating pipelines. Simulation of fragment of DH network in Vilnius and comparison of results with other methods has been carried out as well
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
