| 1. |
- Knight, R, et al.
(författare)
-
GTPOM: Thermo-economic optimization of whole gas turbine plant
- 2006
-
Ingår i: Journal of Engineering for Gas Turbines and Power. - : ASME International. - 1528-8919 .- 0742-4795. ; 128:3, s. 535-542
-
Tidskriftsartikel (refereegranskat)abstract
- Trends towards distributed power generation and the deregulation of energy markets are increasing the requirement for software tools that optimize power generation plant design and operation. In this context, this paper describes the GTPOM (thermo-economic optimization of whole gas turbine plant) European project, funded in part through the European Commissions 5th Framework Programme, focusing on the development and demonstration of an original software tool for the thermo-economic analysis and optimization of conventional and advanced energy systems based on gas turbine plant. PSEconomy, the software tool developed during the GTPOM project, provides a thermo-economic optimization capability for advanced and more-conventional energy systems, enabling the complex trade-offs between system performance and installed costs to be determined for different operational duties and market scenarios. Furthermore, the code is capable of determining the potential benefits of innovative cycles or layout modifications to existing plants compared with current plant configurations. The economic assessment is performed through a complete through-life cycle cost analysis, which includes the total capital cost of the plant, the cost of fuel, O&M costs and the expected revenues from the sale of power and heat. The optimization process, carried out with a GA-based algorithm, is able to pursue different objective functions as specified by the User. These include system efficiency, through-life cost of electricity and through-life internal rate of return. Three case studies demonstrating the capabilities of the new tool are presented in this paper covering a conventional combined cycle system, a biomass plant and a CO2 sequestration gas turbine cycle. The software code is now commercially available and is expected to provide significant advantages in the near and long-term development of energy cycles.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Nydahl, Margaretha, et al.
(författare)
-
Comparison between optical readable and open-ended weighed food records
- 2009
-
Ingår i: Food & Nutrition Research. - : Taylor & Francis. - 1654-6628 .- 1654-661X. ; 53:1, s. 1-8
-
Tidskriftsartikel (refereegranskat)abstract
- Background: A simplified optically readable food record (ORFR) was developed and compared with an openended weighed record (WR). Objective: To compare intake of nutrients and foods using a seven-day ORFR with intake estimated using a seven-day WR. The results from each method were validated against 24-h urine nitrogen excretion and energy intake (EI)/estimated basal metabolic rate (BMR) cut-off values. Design: The study comprised 73 free-living, healthy 70-year-old Swedish men. Dietary data were collected during seven consecutive days, starting either with WR or ORFR. Results: Average intakes of energy and several nutrients were significantly lower when estimated using ORFR than when using WR. However, when adjusted for nutrient density, only a few nutrients were still lower with ORFR. Spearman correlation coefficients between the two methods regarding intakes of energy and energy-yielding nutrients were moderate to high, i.e. 0.4 0.6, while figures for most micro-nutrients were in the range 0.30.5. A large proportion of subjects under-reported their EIs, a higher proportion doing so when using ORFR. Protein intake obtained using ORFR was 31% lower than the values calculated from the 24-h urine nitrogen excretion, and 22% lower than those obtained from WR. Average intakes of milk, cheese and other milk products as well as coffee, tea and alcohol were significantly higher when estimated using ORFR than when using WR, while intakes of vegetables, meat and meat products, fish, bread and cereal products as well as number of sweet foods were significantly lower with ORFR. Conclusions: Based on these results, adjustments of some portion sizes in ORFR are suggested. In view of the advantages of ORFR with respect to lower response burden and rapid processing of data, such adjustments would make ORFR a suitable dietary assessment tool for use in dietary surveys, including larger resourcedemanding epidemiological investigations.
|
|
