Review article
New Stirling Engine Concept (NSC-Engine) with Application of Direct Heat Introduction
Wilhelm Servis
Vladimir Medica
Andrej Korbar
Abstract
The effi ciency of thermal engines is directly dependent on the temperatures and temperature differences of their heat reservoirs (heater
and cooler). Up to now the improvements of the Stirling engine’s effi ciency have been exclusively achieved through the increase of the engine
hot-side temperatures, whereas the possible improvements of the engine thermal effi ciency by lowering their cold-side temperatures, have
not been thoroughly researched.
In the research work of Wilhelm Servis the infl uence of lowering the engine cold-side temperature down to the deep, cryogenic temperature
range on the Stirling engine performance was investigated. The research work results show a regular, very perceptible increase of thermal
effi ciency and brake power by lowering the cold-side temperatures of the investigated engines down to the cryogenic temperature ranges. On
the basis of this investigation it was possible to defi ne a list of measures to be taken to achieve improvements of the classic Stirling engine.
These improvements were achieved through the application of the principle of the direct heat input and output from the engine process, the
realisation of engine cooling through the injection and additional evaporation of liquefi ed working medium in the engine cylinder, and the
engine cooling down to the cryogenic temperature range.
The application of the mentioned measures has led to the development of the “New Stirling Engine Concept (NSC-engine ≡ NKS-motor)”.
These are the engine types PROFIT0, PROFIT1 and PROFIT2, covered by pending and obtained patents. The NSC-engines, realised on
the basis of this “New Concept” have the highest possible achievable thermal effi ciency and power production, substantially higher than the
presently used thermal engines. These engines, will be able to use nearly any energy source (also porter of heat and cold) and also will be
able to operate as real “class zero” or “class ultra low emission” engines (no or very low CO2- and NOx-emissions).
Keywords
aerothermal engine; NSC-engine; Stirling isothermal engine; thermal effi ciency
Hrčak ID:
25255
URI
Publication date:
1.3.2008.
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