| 1. |
- Genrup, Magnus, et al.
(författare)
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Trigeneration: Thermodynamic performance and cold expander aerodynamic design in humid air turbines
- 2003
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Ingår i: American Society of Mechanical Engineers, International Gas Turbine Institute, Turbo Expo (Publication) IGTI. ; 6 A, s. 1-8
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Konferensbidrag (refereegranskat)abstract
- Improving electrical efficiency has been proposed as the most convenient means of reducing, e.g. CO2 emission from power plants. Increasing fuel utilization through combined heat and power generation is another useful measure for emission reduction. Trigeneration technology for the production of heat, power and cooling is an interesting alternative for further improvement of fuel utilization. Previous studies at The Department of Heat and Power Engineering in Lund. Sweden, have shown that wet cycles are the best candidates, with a high potential to achieve fuel utilization higher than 100%, based on the fuel's lower heating value [1, 2, 8]. Apart from high fuel utilization, trigeneration technology can produce cooling without the use of harmful cooling agents. The basic principle of trigeneration is to interrupt the expansion at an elevated pressure level and extract heat from the working medium. The final expansion then takes place at low temperature admission levels resulting in a very low temperature at the turbine exhaust. In this paper results from both thermodynamic analysis of the humid air turbine concept in conjunction with trigeneration. and the expander design criterion required for realization of the last section of the expander are presented. The thermodynamic study gives the boundary conditions for the cold turbine design. Optimum conditions for the inlet to the cold expander are a pressure of 2 to 3 bar and a temperature of 47
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| 2. |
- Lindquist, Torbjörn, et al.
(författare)
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Experimental and theoretical results of a humidification tower in an evaporative gas turbine cycle pilot plant
- 2002
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Ingår i: American Society of Mechanical Engineers, International Gas Turbine Institute, Turbo Expo (Publication) IGTI. ; 2 A, s. 475-484
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Konferensbidrag (refereegranskat)abstract
- The Evaporative Gas Turbine Pilot Plant has been in operation at Lund Institute of Technology in Sweden since 1997. In this cycle low-grade heat in the flue gases is utilized for water evaporation into the compressed air in the humidification tower. This result in, amongst others, power augmentation, efficiency increase and lower emissions. This article presents the experimental and theoretical results of the humidification tower, in which simultaneous heat and mass transfer occurs. A theoretical model has been established for the simultaneous heat and mass transfer occurring in the humidification tower and it has been validated with experiments. The humidification tower in the pilot plant can be operated at several operating conditions. An after-cooler makes it possible to chill the compressor discharge air before entering the humidification tower. The saturation temperature of the incoming compressed air can thereby be varied from 62 to 105°C at the operating pressure of 8 bar(a). It has been shown that the air and water can be calculated throughout the column in a satisfactory way. The height of the column can be estimated with an error of 10% compared with measurements. The results from the model are most sensitive of the properties of the diffusion coefficient, viscosity and thermal conductivity due to the complexity of the polar gas mixture of water and air.
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| 3. |
- Thern, Marcus, et al.
(författare)
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Theoretical and experimental evaluation of a plate heat exchanger aftercooler in an evaporative gas turbine cycle
- 2003
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Ingår i: American Society of Mechanical Engineers, International Gas Turbine Institute, Turbo Expo (Publication) IGTI. ; 3, s. 103-111
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Konferensbidrag (refereegranskat)abstract
- The evaporative gas turbine pilot plant (EvGT) has been in operation at Lund Institute of Technology in Sweden since 1997. This article presents the experimental and theoretical results of the latest process modifications made, i.e. the effect of the installation of an aftercooler. The purpose of the aftercooler is to increase the performance of the cycle by utilizing more low-level heat in the humidification tower. The chosen aftercooler is of plate heat exchanger type, which, is very compact, has high thermal efficiency and low pressure drop. The installation of an aftercooler lowers the temperature of the air entering the humidification tower. This also lowers the temperature of the circulating humidification water, which facilitates the extraction of more low-level heat from the economizer. This low-level heat can be utilized to evaporate more water in the humidification tower and thus increase the gas flow in the expander. The pilot plant has been operated at different loads and the measured results has been evaluated and compared with theoretical models. The performance of a plate heat exchanger in power plant applications has also been evaluated. Experience from the measurements has then been used for the potential cycle calculations. It has been shown that the aftercooler lowers the flue gas temperature in the pilot plant to 93
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