Optimal Multistage Expansion Planning of a Gas Turbine Cogeneration Plant

1996 ◽  
Vol 118 (4) ◽  
pp. 803-809 ◽  
Author(s):  
R. Yokoyama ◽  
K. Ito ◽  
Y. Matsumoto

A multistage expansion planning problem is discussed concerning a gas turbine cogeneration plant for district heating and cooling using an optimization approach. An optimal sizing method for single-stage planning proposed by the authors is extended to this case. Equipment capacities and utility maximum demands at each expansion stage are determined so as to minimize the levelized annual total cost subject to increasing energy demands. A numerical study on a simple-cycle gas turbine cogeneration plant to be installed in a district development project clarifies the relationship between optimal expansion planning and energy demand trend, and shows the effectiveness of the proposed method.

1995 ◽  
Vol 117 (1) ◽  
pp. 53-59 ◽  
Author(s):  
R. Yokoyama ◽  
K. Ito

An optimal planning method for cogeneration plants proposed earlier is extended to the case with multiple optimization criteria. Equipment capacities and utility maximum demands are determined so as to minimize both the annual total cost and the annual primary energy consumption in consideration of plants’ operational strategies for energy demand requirements. This problem is considered as a multi-objective optimization one, and a discrete set of Pareto optimal solutions is derived numerically by the weighting method. Through a numerical study on a simple cycle gas turbine cogeneration plant used for district heating and cooling, a trade-off relationship between the economic and energy-saving properties is clarified.


Author(s):  
R. Yokoyama ◽  
K. Ito

A computer-aided advisory system is proposed which assists operators in operating an industrial gas turbine cogeneration plant rationally from the economic viewpoint. An optimization approach is adopted to acquire knowledge of the plant’s operational strategy. The on/off and rated/part load status for each piece of constituent equipment is determined so as to minimize the hourly operational cost subject to the energy demand requirement. Various restrictions which must be satisfied in a real operation are incorporated simultaneously. The operational strategy by optimization is compared with that by a real operation, using real data measured on several representative days. The operational status obtained for combinations of electricity and steam demands is illustrated by operational maps.


1997 ◽  
Vol 119 (1) ◽  
pp. 131-136 ◽  
Author(s):  
K. Ito ◽  
R. Yokoyama ◽  
Y. Matsumoto

The effect of installing steam-injected gas turbines in a cogeneration plant is analyzed with respect to unit sizing and operational planning. An optimization method is used to determine the capacities of gas turbines and other auxiliary machinery in consideration of their operational strategies for variations of electricity and thermal energy demands. Through a numerical study on a plant for district heating and cooling, it is clarified how the installation of steam-injected gas turbines in place of simple-cycle ones can improve the economic and energy-saving properties. The influence of the capital cost of steam-injected gas turbines on the unit sizing and the above-mentioned properties is also clarified.


1990 ◽  
Vol 112 (1) ◽  
pp. 122-128 ◽  
Author(s):  
K. Ito ◽  
R. Yokoyama ◽  
S. Akagi ◽  
Y. Matsumoto

The influence of fuel cost on the operation is investigated for a gas turbine-waste heat boiler cogeneration plant by an optimal operational planning method. A planning method is first presented by which the operational policy of each piece of constituent equipment is determined so as to minimize the operational cost. Then, a case study is performed for a cogeneration plant used for district heating and cooling. Through the study, it is made clear how the optimal operational policy and the economic or energy conservative properties are influenced by the costs of purchased electric power and natural gas. It is also shown that the optimal operational policy is superior in economy as compared with other conventional ones.


Author(s):  
Ryohei Yokoyama ◽  
Koichi Ito

A rational method of determining the operational strategy of energy supply plants in consideration of equipment startup/shutdown cost is proposed. The operational planning problem is formulated as a large-scale mixed-integer linear programming one, in which on/off status and energy flow rates of equipment are determined so as to minimize the sum of energy supply and startup/shutdown costs over the period considered. By utilizing a special structure of the problem, an algorithm of solving the problem efficiently is proposed. Through a numerical study on the daily operational planning of a gas turbine cogeneration plant for district heating and cooling, the effectiveness of the proposed algorithm is ascertained in terms of computation time, and the influence of equipment startup/shutdown cost on the operational strategy and cost is clarified.


Author(s):  
Satoshi Gamou ◽  
Katsuhiro Joko ◽  
Ryohei Yokoyama ◽  
Koichi Ito

Economic characteristic of micro gas turbine cogeneration systems for commercial and public purposes is evaluated rationally by an optimization method. The number of multiple kinds of micro gas turbine cogeneration units, capacities of other pieces of equipment and utility maximum contract demands are determined so as to minimize the annual total cost in consideration of operational strategies for energy demand requirements. Numerical studies are carried out on systems installed in hotels or office buildings. Through the studies, the following are clarified: (a) the relationships between the number of the installed micro gas turbine cogeneration units and the maximum electricity demands of hotels and office buildings, and (b) the economic effects of the micro gas turbine cogeneration units.


Author(s):  
D. Cerra ◽  
M. Alberdi-Pagola ◽  
T.R. Andersen ◽  
K.W. Tordrup ◽  
S.E. Poulsen

We assess the feasibility of a collective district heating and cooling network based on a foundation pile heat exchanger in a new urban area in Vejle, Denmark. A thermogeological model for the area is developed based on geophysical investigations and borehole information. In tandem with a building energy demand model, the subsurface thermal properties serve as the input for a newly developed computational temperature model for collective heating and cooling with energy piles. The purpose of the model is to estimate the long-term performance and maximum liveable area that the energy piles are able to support. We consider two case studies where residential and office buildings dominate the building mass. We find that three to four floors can be supplied with heating and cooling from the energy piles, depending on the use and design of the buildings.


Proceedings ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
Serafeim Moustakidis ◽  
Ioannis Meintanis ◽  
Nicos Karkanias ◽  
George Halikias ◽  
Elise Saoutieff ◽  
...  

The paper discusses the outcomes of the conference organized by the InDeal project. The conference took place on 12 December 2018 in Montpellier as part of the EnerGaia energy forum 2018. A holistic interdisciplinary approach for district heating and cooling (DHC) networks is presented that integrates heterogeneous innovative technologies from various scientific sectors. The solution is based on a multi-layer control and modelling framework that has been designed to minimize the total plant production costs and optimize heating/cooling distribution. Artificial intelligence tools are employed to model uncertainties associated with weather and energy demand forecasts, as well as quantify the energy storage capacity. Smart metering devices are utilized to collect information about all the crucial heat substations’ parameters, whereas a web-based platform offers a unique user environment for network operators. Three new technologies have been further developed to improve the efficiency of pipe design of DHC systems: (i) A new sustainable insulation material for reducing heat losses, (ii) a new quick-fit joint for an easy installation, and (iii) a new coating for reducing pressure head losses. The results of a study on the development and optimization of two energy harvesting systems are also provided. The assessment of the environmental, economic and social impact of the proposed holistic approach is performed through a life cycle analysis. The validation methodology of the integrated solution is also described, whereas conclusions and future work are finally given.


Author(s):  
Kosuke Kato ◽  
◽  
Masatoshi Sakawa ◽  
Keiichi Ishimaru ◽  
Satoshi Ushiro ◽  
...  

Urban district heating and cooling (DHC) systems operate large freezers, heat exchangers, and boilers to stably and economically supply hot and cold water, steam, etc., based on customer demand. We formulate an operation-planning problem as a nonlinear integer programming problem for an actual DHC plant. To reflect actual decision making appropriately, we incorporate contract-violation penalties into the running cost consisting of fuel and arrangements expenses. We, then, solve operation-planning problems with and without penalties, demonstrating the effectiveness of taking penalties into consideration.


Author(s):  
Ryohei Yokoyama ◽  
Masashi Ohkura ◽  
Tetsuya Wakui

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.


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