(Web ThermoEconomic Modular Program)
W-TEMP code started its life in the 2000s when TPG decided to move to the study and optimization of complex and non-conventional energy systems which need to demonstrate their technical and economic viability. This reason convinced us to develop a detailed software tool for the complete and automatic thermoeconomic analysis of power and cogenerative plants of different types, concepts, and sizes.
Firstly, the basic idea was to create a modular program to allow free development by all the users: such a happy starting point led to a code that, at present, offers you more than 90 modules, and is capable of simulating several types of energy plants (can’t say “all” because it is impossible to know what the future is preparing…) from conventional systems (e.g., combined cycle) to advanced concepts (humid air cycle, fuel cell hybrid system, biomass gasification integrated plant, etc.), automatically provides the user with detailed thermodynamic, exergetic, economic data about both the internal structure of the layout and the plant as a whole. Of course, the obtained results are as accurate as the basic assumptions for the thermodynamic performance and component costs the user has to make.
As always, it is a good idea to be mistrustful of the most trivial results: rather, it is better to value and believe in the results obtained through the efforts and experience of a team of well-established researchers and engineers. This is what we do. So far, we had several occasions to test W-TEMP reliability with industrial and academic data from the field: this allows us to use W-TEMP as our “rule of thumb” for energy plant assessment from the thermoeconomic point of view.
Concept and approach
W-TEMP allows the thermoeconomic and exergoeconomic analysis of a large number of energy cycles such as the following to be obtained: steam, gas turbine, combined, and advanced cycles (mixed gas-steam cycles, biomass gasification integrated plant, fuel cells – SOFC and MCFC – and hybrid cycles, partial oxidation cycles, chemical recovery cycles, integrated solar combined cycles). The system to be calculated is defined as an ensemble of interconnected components.
Operating characteristics and mass and energy balances of each component, in the on-design state, are calculated sequentially until the conditions (pressure, temperature, mass flow, etc.) at all interconnections converge on a stable value. After the thermodynamic calculation, the thermoeconomic analysis is performed: at first each component purchase cost is defined through the use of cost or costing equations, therefore the internal thermoeconomic and exergoeconomic analysis is carried out through the cost and exergy balances of each module.
It is possible to calculate the internal irreversibility of each component (that determines an exergy expenditure) and its capital cost (that determines a monetary expenditure). Thermoeconomic results are given at two different levels: at the inner level as an estimate of the average unit cost, the unit exergetic cost, and the marginal cost at each connection; at the outer level as an evaluation of the thermal efficiency, the generated power, the generated heat, the electrical and thermal energy costs. In addition, it is possible to carry out plant through-life cost analysis, calculating financial parameters such as internal rate of return, payback period, net present value, and others. In the end, the plant’s thermodynamic and economic features are completely and fully described.
The W-TEMP code is also provided with an optimization tool that allows energy system thermoeconomic optimization to be obtained with different objective functions: the most important are thermal efficiency and cost of electricity. The non-linear optimization algorithm has been recently upgraded with the introduction of a genetic algorithm.
In the W-TEMP code, besides the complete thermoeconomic assessment, also the environomic analysis of power plants is available. The criteria that will influence the evolution of the energy market this century will be based on the need to preserve the environment (both locally and globally) through new technologies and sustainable use of existing resources. This need is also ratified by the guidelines of the various pledges of the European Union, the United Nations 2030 Agenda (7th and 13th SDGs), or the Paris Agreement in the framework of IPCC. In particular, the global warming problem, linked to CO2 emissions, requires an energy policy approach at an international level devoted to CO2 regulation: the energy policy should aim at punishing the inefficient use of fossil energy sources that determines a larger emission of CO2 than a more efficient use.
W-TEMP allows the user to evaluate the effects on, for example, the final cost of electricity and the internal rate of return of the plant caused by the introduction of charges on pollutant emissions or fuel taxation. In this respect, W-TEMP is also a powerful tool for evaluating the advantages and drawbacks of policy actions from a microeconomic and macroeconomic perspective. W-TEMP is provided with the complete Carbon Exergy Tax (CET) procedure, proposed by TPG as an effective rule to control CO2 emissions penalizing the most inefficient systems.
Fields of application
W-TEMP can thus be a powerful tool whenever a study or a design of a new or non-conventional energy system is necessary. From simple thermodynamics to exergonomics, mixed analyses and different KPIs can be selected to be analysed or optimised, to help the user explore design possibilities and make the best decision.
Examples of usage are very wide, and range from conventional to innovative GT-based cycles, from traditional steam to cycles evolving organic fluids and supercritical carbon dioxide, from traditional power applications to high temperature heat pumps, from fuel cells to pressure gain combustors.
Publications
Thermoeconomic Analysis of Gas Turbine Based Cycles
A.F. Massardo, M. Scialo’
ASME Transactions, Journal of Engineering for Gas Turbines and Power, Vol. 122, pp. 664-671
WIDGET-TEMP: a novel web-based approach for thermoeconomic analysis and optimization of conventional and innovative cycles
A. Traverso, A.F. Massardo, W. Cazzola, G. Lagorio
Proceedings of the ASME Turbo Expo 2004: Power for Land, Sea, and Air. Volume 7: Turbo Expo 2004. Vienna, Austria. June 14–17, 2004. pp. 623-631. ASME.
Thermoeconomic analysis of SOFC-GT hybrid systems fed by liquid fuels
M. Santin, A. Traverso, L. Magistri, A. Massardo
Energy, Volume 35(2), pp. 1077-1083
Existing large steam power plant upgraded for hydrogen production
L. Galanti, A. Franzoni, A. Traverso, A. Massardo
Applied Energy, Vol. 88, pp.1510-1518
Micro gas turbine thermodynamic and economic analysis up to 500 kWe size
L. Galanti, A. F. Massardo
Applied Energy 88 (2011) 4795–4802
Hydro-methane and methanol combined production from hydroelectricity and biomass: Thermo-economic analysis in Paraguay
M. Rivarolo , D. Bellotti , A. Mendieta , A.F. Massardo
Energy Conversion and Management 79 (2014) 74–84