49 research outputs found
Theoretical analysis of a novel integrated energy system formed by a microturbine and a exhaust fired single-double effect absorption chiller
Integrated Energy Systems (IES) combine a distributed power generation system (DG) such as a microturbine generator (MTG) or a fuel cell with thermally activated technologies (TAT) such as absorption cooling. This integration maximizes the efficiency of energy use by utilizing on-site most of the waste heat generated by DG, and reduces
harmful emissions to the environment. This study investigates the energy and exergy performance of an IES. This system is comprised of an MTG with internal recuperator and a novel absorption cooling cycle. The absorption cycle is a single-double effect exhaust fired cycle, which recuperates the heat exchanged from the MTG exhaust gases using two generators at two different levels of temperature. The selection of the DG element, the TAT element and their internal configurations is based upon a real IES commercial unit that has
been tested in the APEP-UCI DG testing facilities in Irvine, California. This unit has an electrical power capacity of 28 kW and a cooling capacity of 14 refrigeration tons (49.2 kW). Inputs for the thermodynamic models developed for the MTG and for the absorption
cycle are derived from experimental variables that will be controlled in the testing phase. The MTG model is using empirical correlations for key model parameters (pressure ratio, turbine inlet temperature, etc.) from previous studies in order to predict the observed
change in performance with part load operation. The calculated mass flow rate and temperature of the exhaust gases are inputs for the absorption cycle model, together with cooling and chilled water inlet temperatures and flow rates. Heat and mass transferefficiencies along with heat transfer coefficients for the suite of heat exchangers
comprising the single-double effect absorption cycle are determined from proprietary testing data provided by the manufacturers
Influence of the Continuous and Dispersed Phases on the Symmetry of a Gas Turbine Air-Blast Atomizer
INFLUENCE OF THE CONTINUOUS AND DISPERSED PHASES ON THE SYMMETRY OF A GAS-TURBINE AIR-BLAST ATOMIZER
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Effect of fuel injection mode on fuel vapor in reacting and non-reacting methanol sprays
Detailed measurements within sprays are needed to understand the vaporization, transport, and combustion of liquid fuels. While diagnostics have been developed to characterize the structure of the spray droplets in great detail (e.g., phase Doppler interferometry), details regarding the gas phase (e.g., oxidizing media and fuel vapor) are more difficult to obtain. In the present study, measurement of gas phase vector properties are achieved in the spray field of a twin-fluid atomizer using phase Doppler interferometry. A gas phase scalar, the concentration of hydrocarbon vapor, is measured using an infrared extinction/scattering technique. When combined, the two measurements provide a direct measure of the vaporization characteristics of the spray. A methanol spray is studied which is produced by an atomizer operating at three conditions, (1) no atomizing air, (2) non-swirling atomizing air, and (3) swirling atomizing air. The injection mode alters the vaporization behavior of the spray. For the non-reacting cases, (1) the presence of non-swirling air-assist, while not strongly affecting the spatial vaporization history, enhances the temporal vaporization rate compared to the case without atomizing air; (2) the presence of swirling atomizing air greatly enhances the vaporization rate in both space and time; and (3) examination of the rate of change of vaporization reveals a correlation among all three injection modes, suggesting that the fundamental mechanism of vaporization in all three sprays is the same. For the reacting cases, swirling air increases the production of fuel vapor in both time and space compared to the non-swirling air case. The change in vaporization rate shows a trend similar to the non-reacting case, although the rate of change is negative in the region of the reaction zone due to competition between vaporization and consumption. © 1992 Combustion Institute
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Influence of the continuous and dispersed phases on the symmetry of a gas turbine air-blast atomizer
Current trends in liquid-fueled practical combustion systems are leaving less tolerance for fuel injection deficiencies such as poor spray field symmetry. The present paper evaluates the symmetry of the flowfield produced by a practical air-blast atomizer. Specifically, the influence of both the continuous phase and dispersed phase on the sprayfield symmetry is assessed. In the present case, asymmetry in volume flux is associated principally with disparities in the injection of the dispersed phase, which is manifested by a maldistribution of larger drops. Asymmetries observed in the continuous phase without the dispersed phase are reduced in magnitude by the presence of the dispersed phase, but still contribute to asymmetry in radial spread of the dispersed phase
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Effect of fuel injection mode on fuel vapor in reacting and non-reacting methanol sprays
Detailed measurements within sprays are needed to understand the vaporization, transport, and combustion of liquid fuels. While diagnostics have been developed to characterize the structure of the spray droplets in great detail (e.g., phase Doppler interferometry), details regarding the gas phase (e.g., oxidizing media and fuel vapor) are more difficult to obtain. In the present study, measurement of gas phase vector properties are achieved in the spray field of a twin-fluid atomizer using phase Doppler interferometry. A gas phase scalar, the concentration of hydrocarbon vapor, is measured using an infrared extinction/scattering technique. When combined, the two measurements provide a direct measure of the vaporization characteristics of the spray. A methanol spray is studied which is produced by an atomizer operating at three conditions, (1) no atomizing air, (2) non-swirling atomizing air, and (3) swirling atomizing air. The injection mode alters the vaporization behavior of the spray. For the non-reacting cases, (1) the presence of non-swirling air-assist, while not strongly affecting the spatial vaporization history, enhances the temporal vaporization rate compared to the case without atomizing air; (2) the presence of swirling atomizing air greatly enhances the vaporization rate in both space and time; and (3) examination of the rate of change of vaporization reveals a correlation among all three injection modes, suggesting that the fundamental mechanism of vaporization in all three sprays is the same. For the reacting cases, swirling air increases the production of fuel vapor in both time and space compared to the non-swirling air case. The change in vaporization rate shows a trend similar to the non-reacting case, although the rate of change is negative in the region of the reaction zone due to competition between vaporization and consumption. © 1992 Combustion Institute