Testing and Modeling of a Semi-Closed Gas Turbine Cycle Integrated With a Vapor Absorption Refrigeration System

A novel cooling and power cycle has been proposed that combines a semi-closed cycle gas turbine called the High Pressure Regenerative Turbine Engine (HPRTE) with a vapor absorption refrigeration system (VARS). The refrigeration cycle (VARS) interacts with the power cycle (HPRTE) solely through heat transfer in the generator and the evaporator. Waste heat from the recirculated combustion gas of the HPRTE is used to power the absorption refrigeration unit, which cools the high-pressure compressor inlet of the HPRTE to below ambient conditions and also produces excess refrigeration, in an amount which depends on ambient conditions. Water produced as a product of combustion is intentionally condensed in the evaporator of the VARS, which is designed to provide sufficient cooling for three purposes: chilling the inlet air to the high pressure compressor, water extraction, and for an external cooling load. In a previous study, the combined cycle was modeled using zero-dimensional steady-state thermodynamics, with the specified values of efficiencies and pressure drops for the turbo-machinery and heat exchangers. The model predicts that the combined cycle with steam blade cooling for a medium-sized engine will have a thermal efficiency of 49%, in addition to the external refrigeration load generated in the cycle which is 13% of the net work output. It also produces about 1.4 kg of water for each kg of fuel (propane) consumed. A small experimental unit demonstrating the HPRTE/VARS combined cycle has been constructed and is currently being tested in the Energy & Gas-dynamic Systems Laboratory at the University of Florida. A 45 HP Rover 1S-60 engine is integrated with a NH3 /H2 O vapor absorption refrigeration unit having a capacity of 19 Ton Refrigeration. The engine flow-path has been significantly modified to include partial recirculation of exhaust products, turbocharging, and recuperation, thus implementing the HPRTE concept. In addition, a significant modeling effort has been undertaken to simulate the combined cycle operation under design and off-design conditions. Initial experimental results show good agreement with the model predictions, including overall efficiency and water extraction rates.Copyright © 2006 by ASME

[1]  Pedro J. Coelho,et al.  Numerical simulation of a mild combustion burner , 2001 .

[2]  Nebojsa Gasparovic.  THE ADVANTAGE OF SEMI-CLOSED CYCLE GAS TURBINES FOR NAVAL SHIP PROPULSION , 1968 .

[3]  D. Spalding,et al.  INTRODUCTION TO COMBUSTION , 1979 .

[4]  D. R. Stull,et al.  JANAF Thermochemical Tables. Second Edition , 1971 .

[5]  Gunnar Olavi Tamm,et al.  Experimental investigation of an ammonia-based combined power and cooling cycle , 2003 .

[6]  Ch. Trepp,et al.  Equation of state for ammonia-water mixtures , 1984 .

[7]  S. A. Sherif,et al.  Second Law Analysis of a Novel Combined Cooling and Power Cycle With Water Harvesting , 2005 .

[8]  O. M. Ibrahim,et al.  Absorption power cycles , 1996 .

[9]  S. A. Sherif,et al.  Demonstration of a Novel Combined Cooling and Power Gas Turbine with Water Harvesting , 2005 .

[10]  Daniele Fiaschi,et al.  Semi-Closed Gas Turbine/Combined Cycle With Water Recovery and Extensive Exhaust Gas Recirculation , 1996 .

[11]  J. Wunning,et al.  Flameless oxidation to reduce thermal no-formation , 1997 .

[12]  S. H. DeWitt,et al.  Internally Fired Semi-Closed Cycle Gas Turbine Plant for Naval Propulsion , 1956 .

[13]  S. A. Sherif,et al.  Performance of a Novel Semi-Closed Gas Turbine Refrigeration Combined Cycle , 2003 .

[14]  Nishant Muley,et al.  Effect of Exhaust Gas Recirculation on Thermal NOx Formation Rate in Gas Turbine Engines , 2003 .

[15]  R. MacFarlane,et al.  System impact of H2O production and injection on a novel semi-closed cycle gas turbine , 1997 .

[16]  Norbert Peters,et al.  Laseroptical investigation of highly preheated combustion with strong exhaust gas recirculation , 1998 .