Method and Case Study of Multiobjective Optimization-Based Energy System Design to Minimize the Primary Energy Use and Initial Investment Cost

Dong-Seok Kong,Jung-Ho Huh,Yong-Sung Jang

doi:10.3390/en8066114

Abstract

This study aimed to develop a building energy system design method to minimize the initial investment cost and primary energy use. As for the energy system, various combinations were generated depending on the type and capacity of the device used as well as the number of units, energy consumption, and efficiency of the building. Because the design process of energy systems is a critical step in determining the performance of the building throughout the lifecycle, an effective design method is necessary. The proposed method determines the energy system that can minimize the primary energy use and initial investment cost through a multiobjective optimization by calculating the cooling and heating energy consumptions of the building and initial investment cost of the energy system using the load profile by the design-day, and the information in the design phase of the building. This method can support the decision-making process by providing engineers with an alternative proposal for minimizing the initial investment cost and primary energy use by the Pareto analysis after reviewing the design combinations of various energy systems with limited information in the initial design phase. To verify the effectiveness of the methodology, a case study of the two buildings was performed, and the analysis results were compared to the conventional design alternatives. As shown in the case study results, using a method developed in comparison with the conventional result can provide the efficient alternative selection with 80% of initial investment cost and 86% of primary energy use, respectively. The results confirmed that the proposed methodology can provide various optimum results more effectively compared to the conventional design methods.

Highlights

The energy system of a building can yield a variety of combinations depending on the types and capacities of the devices used as well as the number of units and the energy consumption
This study aimed to develop an energy system design method based on the restrictive information in the early stage of the design process by the identification of the constraints and problems in the design process, by reviewing the conventional design approaches for building energy systems and the conventional energy consumption analysis methods
The base represents the energy system designed with the conventional method; the square point shows the optimal solution created by the optimization by applying the GSHP

Summary

Introduction

The energy system of a building can yield a variety of combinations depending on the types and capacities of the devices used as well as the number of units and the energy consumption. The efficiency of a building during its lifecycle is determined by various combinations of the devices. In most of the cases, business constraints such as lack of time for review, lack of design information, institutional restrictions, and client requirements fail to investigate various design combinations. For this reason, the conventional designs have been dependent on the ability of the experts to review a small number of design alternatives. The conventional designs have been dependent on the ability of the experts to review a small number of design alternatives This tends to oversize [1]

Methods

Results

Conclusion