Optimal Sizing of a Gas Turbine Cogeneration Plant in Consideration of Its Operational Strategy

1994 ◽  
Vol 116 (1) ◽  
pp. 32-38 ◽  
Author(s):  
R. Yokoyama ◽  
K. Ito ◽  
Y. Matsumoto
Keyword(s):  
Programming Problem ◽  
Gas Turbine ◽  
Mixed Integer ◽  
Turbine Plant ◽  
Operational Strategies ◽  
Integer Linear Programming Problem ◽  
Energy Demands ◽  
Annual Total ◽  
Planning Problems ◽  
Annual Total Cost

An optimal planning method is proposed for the fundamental design of cogeneration plants. Equipment capacities and utility maximum demands are determined so as to minimize the annual total cost in consideration of the plants’ annual operational strategies for the variations of both electricity and thermal energy demands. These sizing and operational planning problems are formulated as a nonlinear programming problem and a mixed-integer linear programming problem, respectively. They are solved efficiently in consideration of their hierarchical relationship by a penalty method. A numerical example about a gas turbine plant is given to ascertain the validity and effectiveness of the proposed method.

Analysis of Optimal Unit Numbers and Sizes for Microturbine Cogeneration Systems

2004 ◽  
Author(s):  
Satoshi Gamou ◽  
Koichi Ito ◽  
Ryohei Yokoyama
Keyword(s):  
Energy Demand ◽  
Large Scale ◽  
Maximum Energy ◽  
Mixed Integer ◽  
Small Scale ◽  
Optimization Approach ◽  
Operational Strategies ◽  
Energy Demands ◽  
Exhaust Heat ◽  
Annual Total

The relationships between unit numbers and capacities to be installed for microturbine cogeneration systems are analyzed from an economic viewpoint. In analyzing, an optimization approach is adopted. Namely, unit numbers and capacities are determined together with maximum contract demands of utilities such as electricity and natural gas so as to minimize the annual total cost in consideration of annual operational strategies corresponding to seasonal and hourly energy demand requirements. This optimization problem is formulated as a large-scale mixed-integer linear programming one. The suboptimal solution of this problem is obtained efficiently by solving several small-scale subproblems. Through numerical studies carried out on systems installed in hotels by changing the electrical generating/exhaust heat recovery efficiencies, the initial capital cost of the microturbine cogeneration unit and maximum energy demands as parameters, the influence of the parameters on the optimal numbers and capacities of the microturbine cogeneration units is clarified.

Performance Evaluation of Gas Turbine Cogeneration Plants Using a Design Optimization Tool: OPS-Design

2006 ◽  
Author(s):  
Ryohei Yokoyama ◽  
Koichi Ito
Keyword(s):  
Design Optimization ◽  
Gas Turbine ◽  
Graphical Representation ◽  
Primary Energy ◽  
Mixed Integer ◽  
Automatic Programming ◽  
Operational Strategies ◽  
Data Registration ◽  
Energy Demands ◽  
User Friendly

To attain the highest performance of gas turbine cogeneration plants, it is important to rationally determine their structures as well as equipment numbers and capacities in consideration of their operational strategies corresponding to seasonal and hourly variations in energy demands. However, it needs much task and time. In this paper, a design optimization tool named “OPS-Design” is developed to determine the structures as well as equipment numbers and capacities for given super structures of energy supply plants. This tool uses optimization approaches based on the mixed-integer linear programming, and has a user-friendly interface for the functions of data registration, graphical flowsheet editing, automatic programming and optimization calculation, and graphical representation of results. In addition, the performance of a gas turbine cogeneration plant is evaluated using the tool in terms of the annual total cost and primary energy consumption. It is demonstrated that the tool is very effective to evaluate the performance rationally, easily, and flexibly.

An Optimal Renewal Planning of Energy Supply System From Economic Viewpoint

2005 ◽  
Author(s):  
Shu Yoshida ◽  
Satoshi Gamou ◽  
Koichi Ito ◽  
Toshinori Enokido ◽  
Ryohei Yokoyama
Keyword(s):  
Energy Supply ◽  
Energy Demand ◽  
Numerical Study ◽  
Steam Boiler ◽  
Operational Strategies ◽  
Energy Supply System ◽  
Annual Total ◽  
Supply Systems ◽  
Annual Total Cost ◽  
Selection Of

An optimal planning method of renewal planning for energy supply systems is proposed to determine the proper renewal year and selection as to what kind of equipment is suitable for several types of buildings from economic viewpoint. In this method, they are determined together with maximum contract demands of utilities such as electricity and natural gas so as to minimize the annual total cost in consideration of system’s annual operational strategies corresponding to seasonal and hourly energy demand requirements during every evaluation year considered. A numerical study is carried out for an office building with a total floor area of 15 000m2, where the system is consisted of an electric refrigerator and a steam boiler. Through the numerical calculation, the influence of the following items are clarified on the optimal renewing year and selection of renewing equipment of the system by the parametric study; (a) upgrading technology of the equipment in the future; (b) initial capital cost of equipment; (c) renewing construction cost and trade-in value rate; and (d) interest rate.

Robust Optimal Operation of a Gas Turbine Cogeneration Plant Under Uncertain Energy Demands

2014 ◽  
Vol 137 (2) ◽  
Author(s):  
Ryohei Yokoyama ◽  
Masashi Ohkura ◽  
Tetsuya Wakui
Keyword(s):  
Gas Turbine ◽  
Energy Supply ◽  
Numerical Study ◽  
Optimization Method ◽  
Optimal Operation ◽  
Mixed Integer ◽  
Cogeneration Plant ◽  
Co2 Emission Reduction ◽  
Operational Strategy ◽  
Energy Demands

Some optimal operation methods based on the mixed-integer linear programming (MILP) have been proposed to operate energy supply plants properly from the viewpoints of economics, energy saving, and CO2 emission reduction. However, most of the methods are effective only under certain energy demands. In operating an energy supply plant actually, it is necessary to determine the operational strategy properly based on predicted energy demands. In this case, realized energy demands may differ from the predicted ones. Therefore, it is necessary to determine the operational strategy so that it is robust against the uncertainty in energy demands. In this paper, an optimization method based on the MILP is proposed to conduct the robust optimal operation of energy supply plants under uncertain energy demands. The uncertainty in energy demands is expressed by their intervals. The operational strategy is determined to minimize the maximum regret in the operational cost under the uncertainty. In addition, a hierarchical relationship among operation modes and on/off states of equipment, energy demands, and energy flow rates of equipment is taken into account. First, a general formulation of a robust optimal operation problem is presented, which is followed by a general solution procedure. Then, in a numerical study, the proposed method is applied to a gas turbine cogeneration plant for district energy supply. Through the study, some features of the robust optimal operation are clarified, and the validity and effectiveness of the proposed method are ascertained.

Analysis of Electric Wheeling on Cooperative Fuel Cell Cogeneration Systems Installed in Multi-Areas

1994 ◽  
Vol 116 (3) ◽  
pp. 211-217 ◽  
Author(s):  
K. Ito ◽  
R. Yokoyama ◽  
S. Gamou ◽  
Y. Matsumoto
Keyword(s):  
Fuel Cells ◽  
Primary Energy ◽  
Optimization Approach ◽  
Total System ◽  
Operational Strategies ◽  
Total Cost ◽  
Electrical Grid ◽  
Numerical Studies ◽  
Annual Total ◽  
Annual Total Cost

The influence of electric wheeling—mutual accommodation of electric supply through an electrical grid—on both economical and energy-saving properties of cogeneration systems installed in multi-areas is investigated. An optimization approach is adopted to evaluate a critical influence of electric wheeling and to determine the systems’ sizes and operational strategies rationally. Equipment capacities and maximum contract demands of utilities in each area are determined so as to minimize the annual total cost of the total system in consideration of operational strategies for energy supply to the respective areas and mutual electric wheeling. Numerical studies are carried out on the total system with fuel cells by restricting the total number of multi-areas to two. The results show that the introduction of electric wheeling brings little reduction of both the annual total cost and the annual primary energy consumption, in spite of reflecting the optimal utilization of fuel cells through the wheeling function.

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