Effect of initial systems on the renewal planning of energy supply systems for a hospital

Shu Yoshida, Koichi Ito, Yoshiharu Amano, Shintaro Ishikawa, Takahiro Sushic, Takumi Hashizume

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

In recent years, many types of energy supply systems have come into use in various buildings for spaceheating/ cooling and hot water supply. Lifetimes of buildings are generally more than 60 years, but those of energy supply systems are around 15~25 years. Therefore, these systems must be renewed several times during lifetimes of buildings. In the study, this renewal planning problem is formulated mathematically as an optimization one, in which the objective function to be minimized is the average value of annual total cost during system's evaluation period. Namely, this optimization problem is formulated as a large-scale mixed-integer linear programming problem, and the programming language AMPL solver is adopted here as the solving tool to derive the numerical solution. A numerical study is carried out for a hospital with the total floor area of 25 000m2, where electrical (e.g., heat pump) and gas (e.g., gas engine cogeneration) systems are compared together with their hybrid system. The analysis is particularly focused on the influence of initial system's difference on the renewal planning of energy supply system. Through this study, the following results are mainly obtained: a) If the initial system is gas one, it is better to renew it to the electrical one as soon as possible due to relatively low energy efficiency of gas utilizing pieces of equipment, the high price of gas input energy in Japan, and so on. b) If the initial system is electrical one, the optimal renewal year becomes relatively later year, because it is economically better to use the initially installed high efficiency system as long as possible. c) Theoretically, the hybrid system is of course the best renewal one. However, there is no economic difference between the hybrid and the electrical systems.

Original languageEnglish
Title of host publicationProceedings of the 25th International Conference on Efficiency, Cost, Optimization and Simulation of Energy Conversion Systems and Processes, ECOS 2012
PublisherAabo Akademi University
Pages107-118
Number of pages12
ISBN (Print)9788866553229
Publication statusPublished - 2012 Jan 1
Event25th International Conference on Efficiency, Cost, Optimization and Simulation of Energy Conversion Systems and Processes, ECOS 2012 - Perugia, Italy
Duration: 2012 Jun 262012 Jun 29

Publication series

NameProceedings of the 25th International Conference on Efficiency, Cost, Optimization and Simulation of Energy Conversion Systems and Processes, ECOS 2012
Volume7

Conference

Conference25th International Conference on Efficiency, Cost, Optimization and Simulation of Energy Conversion Systems and Processes, ECOS 2012
CountryItaly
CityPerugia
Period12/6/2612/6/29

Keywords

  • Energy supply system
  • Hospital
  • Initial system
  • Optimization
  • Renewal planning

ASJC Scopus subject areas

  • Energy(all)
  • Environmental Science(all)

Fingerprint Dive into the research topics of 'Effect of initial systems on the renewal planning of energy supply systems for a hospital'. Together they form a unique fingerprint.

Cite this