Insertion of Shock Wave Compression Technology Into Micro Turbines for Increased Efficiency and Reduced Costs

Abstract

The following analysis is presented to serve as a preliminary design guide for micro turbine engine designers to consider the potential advantages of incorporating the Rampressor into their recuperated engine designs. It is shown that the increase in compressor efficiency and the shift in optimum pressure will increase the efficiency of the engine and lower the recuperator inlet temperature and specific cost. This also provides the opportunity to increase the turbine inlet temperature and specific power without incorporating more costly air-cooled metal or ceramic components into the turbine design. Ramgen Power Systems, Inc. (RPS) is developing a family of high performance supersonic compressor designs that combine many of the aspects of shock compression systems, commonly used in supersonic flight inlet design, with turbo-machinery design practices employed in conventional axial and centrifugal compressor design. The result is a high efficiency compressor that is capable of single stage pressure ratios in excess of those available in existing axial or centrifugal compressor designs. This technology provides a tremendous opportunity for replacement and/or de-staging of multi-stage centrifugal or axial compressors in gas turbines for greater efficiency, less cost, fewer parts, lower weight, and reduced footprint. A conceptual single-stage supersonic compressor has been defined for integration with a micro turbine in the 200 to 500 kWe class. This configuration offers the potential to achieve the DOE Advanced Micro Turbine Systems goals of greater than 40% LHV electric efficiency and $500 per kWe package selling price.

Study of KJ-66 micro gas turbine compressor: Steady and unsteady Reynolds-averaged Navier–Stokes approach

“…A conjugate solver was developed, aiming to quantify and reveal contributing mechanisms of heat transfer. Steele et al 30 have introduced the concept of combining shock compression system with conventional compressor design, to increase efficiency and reduce costs. The technology offered potential advantages of greater efficiency, fewer parts, lower weight, etc.…”

A Numerical Study for Flow Excitation and Performance of Rampressor Inlet considering Rotor Motion

“…The following parameters are defined to analyze the performances of Rampressor inlet flow path for different operating conditions [4,7].…”

“…Shock wave compression system is employed in the Rampressor inlet. Compared with traditional axial or centrifugal compressor, Ramgen engine has some distinct technical characteristics [3][4][5] such as a higher stage pressure ratio, greater compression efficiency, higher operational reliability, and smaller volume and compact structure.…”

Effect of vane opening on aerodynamic performance of the ram-rotor test system

“…As a supersonic compressor rotor, the ram-rotor is competitive in size and can obtain high single stage total pressure ratio in the meantime. Till now many efforts have been devoted to the design method, flow characteristic prediction and performance test [1][2][3][4][5][6][7][8]. Some power machinery control techniques are used to regulate aerodynamic loading and mass flow rate of compressors at part load and rotational speed conditions, so as to make the compressor run efficiently and steadily.…”