Construction and Performance Evaluation of Prototype Atmospheric Pressure Turbine (APT)

Abstract

This research seeks to propose an atmospheric pressure turbine (ATP), based on the Inverted Brayton Cycle, which puts new, distributed power generation technology to practical use by using various gases at normal pressures and high temperature, from industrial furnaces, waste gasification furnaces, gas turbines, and fuel cells which work at high temperatures, (ex. MCFC: Molten Carbonate Fuel Cell, SOFC: Solid Oxide Fuel Cell) and attempts to save energy and reduce CO2. However, no research has been presented about the operation of a real APT. This paper describes a review of the effectiveness of APT, and shows an outline for the results of a trial run, as well as the production of an APT prototype. The simulation results using a process simulator “HYSYS” show that a 30 kW system has a generator end efficiency (LHV) of about 32%, which is comparable to the performance of other equipment of a similar power rating, such as micro gas turbines. Based on this simulation result we build a 3–5 kW APT prototype and operate. The result of this operation clarifies the basic characteristics of an APT including a performance of 8.7% thermal efficiency. An APT has a smaller specific power than a gas turbine. Accordingly, since its mechanical and dissipative heat losses are larger by comparison, it is important to reduce these losses to attain higher efficiency. Our APT was operated stably and the possibility can be used as a new system for distributed power generation using waste heat was confirmed.

Experimental Investigation of an Inverted Brayton Cycle for Exhaust Gas Energy Recovery

“…Agelidou et al [28] operated a conventional micro gas turbine on an inverted cycle and were unable to produce a positive power output due to high mechanical losses. Inoue et al [29] built a 3.5 kW recuperated microturbine operating on the inverted Brayton cycle. It was referred to as an atmospheric pressure turbine and achieved a maximum thermal efficiency of 8.7%.…”