Identification of design criteria for district cooling distribution network with loop-type system

• Main Authors: Augusto, Gerardo L., Culaba, Alvin B.
• Format: text
• Published: Animo Repository 2019
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/952; https://animorepository.dlsu.edu.ph/context/faculty_research/article/1951/type/native/viewcontent
• Institution: De La Salle University

© 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of ICAE2018 - The 10th International Conference on Applied Energy. The most expensive portion of a large-scale district cooling system is the distribution network that conveys chilled-water to multiple buildings at controlled rates for use in comfort cooling. As the piping system needs large initial investment cost, a thorough investigation would be required to properly design the network. In order to come up with the solution a methodology for an optimal design of district cooling distribution network with loop-type system is needed. In this study, a district cooling distribution network model with loop-type system was investigated by calculating the system pressure drop, system volumetric flow rate and volumetric flow rate for each building. Friction factor identification, system simulation and optimization were performed based on the design temperature difference of 9°C with supply temperature of 4.5°C. The governing equations consisted of mass conservation, performance curve of variable primary flow pumping scheme, energy equations due to pipe friction and an equation that indicates the algebraic sum of head losses around any closed loop must be zero. Multivariable Newton-Raphson method was used to solve the system of nonlinear equations with the elements of solution vector determined using singular-value decomposition method. Exhaustive search method was used to solve the objective function and subsequently determine the piping network design criteria that yields minimum overall cost. Numerical results were also compared with traditional methods and have found some degree of similarities of pipe sizes except for pressure drop values exceeding 100 Pa/m.