Enhancing micro gas turbine performance through fogging technique: Experimental analysis M. Renzi a,⇑ , F. Caresana b , L. Pelagalli b , G. Comodi b a Libera Università di Bolzano, Facoltà di Scienze e Tecnologie, piazza Università, 5 39100 Bolzano, Italy b Dipartimento di Ingegneria Industriale e Scienze Matematiche, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy highlights  A test bench that has been designed to implement the fogging IAC technique to a MGT.  Electric power gain depends on ambient humidity and it ranges from 5% to 13%.  Electric power enhancement is 1.03 kW/°C of inlet air temperature reduction.  Electric conversion efficiency increases by about 0.41%/°C.  Performance gains are the higher, the hotter and drier the climate is. graphical abstract article info Article history: Received 18 April 2014 Received in revised form 2 August 2014 Accepted 21 August 2014 Available online 16 September 2014 Keywords: Inlet air cooling Fogging Micro gas turbine abstract This paper describes a test bench that has been designed to implement the fogging inlet air cooling tech- nique to a 100 kWe Microturbine (MGT) and reports the power and efficiency increase of the machine. Indeed, one of the main issues of MGTs, which has also been observed and documented in large sized gas turbines, is their strong sensibility to inlet air temperature. One of the most interesting technology in terms of low plant complexity to limit the MGTs performance loss is the high pressure fogging. Although cooling down the inlet air temperature with this technique has already been analyzed for med- ium/large gas turbines systems, there are very limited reports available on MGTs and few experimental data are documented. Results show that the machine’s electric power gain depends on ambient humidity and it ranges from 5% to 13% (corresponding to an inlet temperature drop between 4 and 10 °C) in the location where the plant is installed. Power enhancement corresponds to 1.03 kW for each Celsius degree of inlet air temper- ature reduction. As regards the electric conversion efficiency, the increase reaches about 0.41%/°C. Being the inlet air saturation the thermodynamic limit, the absolute power and efficiency gains are the higher, the hotter and drier the climate is. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Microturbines (MGTs) are a relatively new technology that is currently attracting a lot of interest in the distributed generation (DG) market [1–4]. Their electric output varies from 25 kW to 500 kW, which is a power range particularly well suited for http://dx.doi.org/10.1016/j.apenergy.2014.08.084 0306-2619/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +39 0471 017816; fax: +39 0471 017009. E-mail address: massimiliano.renzi@unibz.it (M. Renzi). Applied Energy 135 (2014) 165–173 Contents lists available at ScienceDirect Applied Energy journal homepage: www.elsevier.com/locate/apenergy