Paper 6: Industrial and Marine Gas Turbines of High Specific Power Output

Author(s):  
W. U. Snell
Author(s):  
Claus Linnemann ◽  
Mike W. Coney ◽  
Anthony Price

A novel high efficiency reciprocating piston engine — the isoengine — is predicted to achieve net electrical efficiencies of up to 60% in units of 5 to 20 MWe size. The high efficiency and at the same time a high specific power output are achieved by integrating isothermal compression, recuperative preheating and isobaric combustion into a novel power cycle. The isoengine can utilize distillate oil, natural gas or suitable biofuels. While the first commercial isoengine is envisaged to have a power output of 7 MW, a 3 MW prototype engine is currently being tested. Since compression and combustion are performed in different cylinders, these processes can also be performed at different times such that the isoengine can be used to create a highly efficient small-scale compressed air energy storage (CAES) system. In such configuration, the engine can operate at more than 140% nominal load for a limited time, which depends on the air storage capacity.


Author(s):  
Ali S. Alsagri ◽  
Andrew Chiasson ◽  
Ahmad Aljabr

A thermodynamic analysis and optimization of four supercritical CO2 Brayton cycles were conducted in this study in order to improve calculation accuracy; the feasibility of the cycles; and compare the cycles’ design points. In particular, the overall thermal efficiency and the power output are the main targets in the optimization study. With respect to improving the accuracy of the analytical model, a computationally efficient technique using constant conductance (UA) to represent heat exchanger performances is executed. Four Brayton cycles involved in this compression analysis, simple recaptured, recompression, pre-compression, and split expansion. The four cycle configurations were thermodynamically modeled and optimized based on a genetic algorithm (GA) using an Engineering Equation Solver (EES) software. Results show that at any operating condition under 600 °C inlet turbine temperature, the recompression sCO2 Brayton cycle achieves the highest thermal efficiency. Also, the findings show that the simple recuperated cycle has the highest specific power output in spite of its simplicity.


Author(s):  
Cesar Celis ◽  
Sergio Peralta ◽  
Walter Galarza

Abstract The influence of different power augmentation techniques used in gas turbines on the performance of simple cycle type power plants is assessed in this work. A computational model and tool realistically describing the performance of a typical simple cycle type power plant at design and off-design point conditions is initially developed. This tool is complemented with different models of power augmentation technologies. Finally, the whole model including both power plant and power augmentation techniques is used to analyze a case study involving a particular power plant in Peru. The results from the simulations of the specific power plant indicate that power output can be increased through all the evaluated power augmentation technologies. These results show indeed that technologies based on absorption refrigeration systems produce the largest gains in terms of power output (7.1%) and thermal efficiency (0.7%). Such results confirm the suitability of these systems for simple cycle type power plant configurations operating under hot and humid operating conditions as those accounted for here. From an economic perspective, considering the net present value as the key parameter defining the feasibility of a project in this category, power augmentation techniques based on absorption cooling systems result also the most suitable ones for the studied power plant. Power augmentation techniques environmental implications are also quantified in terms of CO2 emissions.


Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4037 ◽  
Author(s):  
Mikhail Tokarev

A full scale lab prototype of an adsorptive heat transformer (AHT), consisting of two adsorbers, an evaporator, and a condenser, was designed and tested in subsequent cycles of heat upgrading. The composite LiCl/SiO2 was used as an adsorbent with methanol as an adsorbtive substance under boundary temperatures of TL/TM/TH = −30/20/30 °C. Preliminary experiments demonstrated the feasibility of the tested AHT in continuous heat generation, with specific power output of 520 W/kg over 1–1.5 h steady-state cycling. The formal and experimental thermal efficiency of the tested rig were found to be 0.5 and 0.44, respectively. Although the low potential heat to be upgraded was available for free from a natural source, the electric efficiency of the prototype was found to be as high as 4.4, which demonstrates the promising potential of the “heat from cold” concept. Recommendations for further improvements are also outlined and discussed in this paper.


Author(s):  
D H Rix

This paper describes the design considerations that were involved in the production of a prototype Stirling engine, primarily intended for use in a domestic scale combined heat and power (CHP) system. These are discussed in terms of the specification of basic design parameters—configuration, working fluid, etc. First the particular requirements of this application are considered, primarily a power output of 1 kW or less, suitability for high-volume mass production, ultra long life and as high an efficiency as possible. The design that emerges is relatively simple, of low specific power output and with rather conservative operating parameters—temperature, pressure and speed.


1993 ◽  
Author(s):  
Herman B. Urbach ◽  
Donald T. Knauss ◽  
David B. Patchett ◽  
John G. Purnell ◽  
Rolf K. Muench ◽  
...  

The steam-augmented gas turbine (SAGT) has attracted attention because of its increased fuel efficiency. It yields significant, cost-effective increments of output power, particularly when steam/water injection is increased to levels approaching 50% of air flow. Such high levels of steam/water consumption permit burner operation near stoichiometric combustion ratios with specific powers exceeding 580 hp-sec/lb anticipated. This paper examines steam-augmented gas turbines for their applicability in Navy DDG-class ship environments. SAGT engine concepts exhibit efficiencies approaching the Navy’s intercooled regenerative (ICR) engine, and an impressive compactness that arises from the high specific power of steam. Polished water consumption may be 425,000 gal/day for a 100,000-hp SAGT-engine ship plant. Nevertheless, SAGT engine systems impose little if any negative ship impact even after accounting for water purification systems. Moreover, because of their high specific power, SAGT systems are as affordable, on a first-acquisition-cost basis, as the current gas turbine systems in the fleet, and in the present supply pipeline.


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