Abstract
Organic Rankine Cycle (ORC) power systems are nowadays an option for local and domestic cogeneration of heat and electric power. Very interesting are micropower systems for heat recovery from low potential (40–90 °C) waste and renewable heat sources. Designing an ORC system dedicated to heat recovery from such a source is very difficult. Most important problems are connected with the selection of a suitable expander. Volumetric machines, such as scroll and screw expanders, are adopted as turbine alternative in small-power ORC systems. However, these machines are complicated and expensive. Vane expanders on the other hand are simple and cheap. This paper presents a theoretical and experimental analysis of the operation of a micro-ORC rotary vane expander under variable heat source temperature conditions. The main objective of this research was therefore a comprehensive analysis of relation between the vane expander output power and the heat source temperature. A series of experiments was performed using the micropower ORC test-stand. Results of these experiments are presented here, together with a mathematical description of multivane expanders. The analysis presented in this paper indicates that the output power of multivane expanders depend on the heat source temperature, and that multivane expanders are cheap alternatives to other expanders proposed for micropower ORC systems.
Highlights
The Application of Volumetric Expanders in Organic Rankine Cycle (ORC) SystemsEffective energy recovery from renewable and waste energy sources is one of the most important present-day problems [1]
The multivane expander output power mainly depends on the expansion ratio [17], which is a characteristic feature of the machine and it can reach different values
This paper presents a theoretical and experimental analysis of operation of a the micro-ORC rotary vane expander under variable heat source temperature conditions
Summary
Effective energy recovery from renewable and waste energy sources is one of the most important present-day problems [1]. ORCs the applicability of turbines is very limited due to the machine operational characteristics requiring large working medium flows. Screw, spiral, vane and the rotary lobe expanders can be applied in small and micro ORC plants. Modified and specially adapted spiral and screw compressors are often applied as expanders in micro and small ORC systems [6]. These machines are complicated to design and manufacture and are expensive. Encouraged by the abovementioned advantages of vane expanders, the author decided to examine their practical application in a micro-ORC system For this purpose a test-stand, described in detail later in this article, was designed and set up. The following aspects are treated : the assembly and mathematical description of a rotary vane expander and the results of experiments
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
