TY - GEN

T1 - Design and modelling of a novel compact power cycle for low temperature heat sources

A1 - Wronski,Jorrit

A1 - Skovrup,Morten Juel

A1 - Elmegaard,Brian

A1 - Rislå,Harald Nes

A1 - Haglind,Fredrik

AU - Wronski,Jorrit

AU - Skovrup,Morten Juel

AU - Elmegaard,Brian

AU - Rislå,Harald Nes

AU - Haglind,Fredrik

PY - 2012

Y1 - 2012

N2 - Power cycles for the efficient use of low temperature heat sources experience increasing attention. This paper describes an alternative cycle design that offers potential advantages in terms of heat source exploitation. A concept for a reciprocating expander is presented that performs both, work extraction and heat addition. Heated by thermal oil, evaporation takes place in two expansion chambers with a transfer of <br/>the working fluid at an intermediate pressure level. Using saturated liquid as feed leads to an expansion in the two-phase domain. A dynamic model of this expander is used to determine the state of the working fluid during the process. Based on this model, a first optimisation by means of changed valve timing is conducted and the results of this scenario are shown in this paper. The heat transfer during expansion is investigated and used to establish a representation of the dynamic calculation results for use with a steady state cycle evaluation. An organic Rankine cycle model is developed and used for a comparison. The performance of the expander itself and the different requirements regarding heat source and temperature levels are studied.

AB - Power cycles for the efficient use of low temperature heat sources experience increasing attention. This paper describes an alternative cycle design that offers potential advantages in terms of heat source exploitation. A concept for a reciprocating expander is presented that performs both, work extraction and heat addition. Heated by thermal oil, evaporation takes place in two expansion chambers with a transfer of <br/>the working fluid at an intermediate pressure level. Using saturated liquid as feed leads to an expansion in the two-phase domain. A dynamic model of this expander is used to determine the state of the working fluid during the process. Based on this model, a first optimisation by means of changed valve timing is conducted and the results of this scenario are shown in this paper. The heat transfer during expansion is investigated and used to establish a representation of the dynamic calculation results for use with a steady state cycle evaluation. An organic Rankine cycle model is developed and used for a comparison. The performance of the expander itself and the different requirements regarding heat source and temperature levels are studied.

UR - http://www.ecos2012.unipg.it/public/proceedings/html/SECS.html

BT - Proceedings of ECOS 2012

T2 - Proceedings of ECOS 2012

A2 - Sciubba,Enrico

ED - Sciubba,Enrico

ER -