Experimental and Theoretical Results of a Humidification Tower in an Evaporative Gas Turbine Cycle Pilot Plant

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.

Design Point Performance and Optimization of Humid Air Turbine Power Plants

“…Once the invariants are calculated, the equations of station "1" (Equations (A7) and (A8)) allow the solution for the water outlet conditions. This model has been validated against experimental results of a HAT pilot cycle obtained by Lindquist et al [17] and the maximum error in the outlet proprieties of the two streams is 1.5% as reported in Table A1. …”

“…Thus, it allows the derivation of the tower's key dimensions-i.e., the height and diameter of the packing-on a single iterative process, as the thermodynamic performance is defined by the cycle. The model was validated against experimental data presented by Lindquist et al [17] and the results are presented in Table A2. The cost of the tower was calculated based on the shell weight and the packing volume.…”

Experimental and theoretical studies on air humidification by a water spray at elevated pressure

“…A theoretical model using HTU-NTU method to predict packing height for the pressured air humidification process was established and validated with the experiments. The model produced an error of 10% for the prediction of packing height [11]. Several studies [12,13] conducted for predicting the on-design and offdesign characteristics of humidification tower considered the droplet condensation when the gas saturated in the tower.…”

“…Based on McCabe and Smith method, Enick developed a computer model for high-pressure gas humidification, which utilized the discrete form of the mass and heat transfer equation, Redlich-KwongUnNIFAC equation of state in Aspen Plus TM , and the Lewis Relation. In recent studies, several different types of humidification towers are proposed [9][10][11], and emphasis has been given to packed bed towers for humidification. In the first EvGT pilot plant of Lund Institute of Technology, a humidification tower with arranged packing was built and evaluated.…”

Flexible Micro Gas Turbine Rig for Tests on Advanced Energy Systems

“…However, the microturbine (mGT) technology (Kolanowski, 2004) allows wide-ranging experimental activities on small size gas turbine cycles with a strong cost reduction. Moreover, this technology is promising from co-generative (and tri-generative) application point of view (Boyce, 2010), and is essential for advanced power plants, such as hybrid systems , humid cycles (Lindquist et al, 2002), or externally fired cycles (Traverso et al, 2006). However, if microturbine standard cycle is modified by introducing innovative components, such as fuel cells (Magistri et al, 2002, saturators (Pedemonte et al, 2007) or new concept heat exchangers (such as ceramic recuperators (McDonald, 2003)), at least two main aspects have to be considered:  avoiding dangerous conditions (e.g.…”