Geothermal power plants with maximized specific power output: Optimal working fluid and operating conditions of subcritical and transcritical Organic Rankine Cycles. (November 2016)

• Record Type: Journal Article
• Authors: Chagnon-Lessard, Noémie; Mathieu-Potvin, François; Gosselin, Louis
• Is Part Of: Geothermics. Volume 64(2016:Nov.)
• Page Start: 111
• Page End: 124
• Publication Date: 2016-11
• Subjects: CO condenser -- EC economizer -- EV evaporator -- HE heat exchanger -- ORC organic rankine cycle -- PP pump -- TB turbine -- SH superheater; Geothermal power plant -- Organic Rankine Cycle -- Thermodynamic numerical simulation -- Optimization -- Design chart; Hydrogeology -- Periodicals; Geothermal resources -- Periodicals; Énergie géothermique -- Périodiques; GEOTHERMAL ENGINEERING; GEOTHERMAL ENERGY; GEOTHERMAL EXPLORATION; Geothermal resources; Hydrogeology; Periodicals; Electronic journals; 621.44
• DOI: 10.1016/j.geothermics.2016.04.002
• Languages: English
• ISSNs: 0375-6505

Abstract

Highlights: An Organic Rankine Cycle (ORC) is optimized by means of numerical simulations. Subcritical and transcritical cycles are considered, and 36 fluids are compared. A wide range of condenser temperature and of geofluid temperature is investigated. Optimization results are summarized in design charts. A simple correlation is developed to predict the maximal specific output of an ORC. Abstract: In this paper, the design of an Organic Rankine Cycle (ORC) is optimized by means of numerical simulations. The systems of interest are the subcritical and transcritical thermodynamic cycles. Optimizations are performed with the objective of determining the design that maximizes the specific power output. The design variables include the operating parameters (pressures, mass flow rates), and the best working fluid is determined by comparing the performance of 36 refrigerants. Optimization runs are performed for a wide range of geofluid temperatures (from 80 to 180 °C), and for a wide range of condenser temperature (from 0.1 to 50 °C). The results are summarized in charts that may be used as efficient tools for designing optimal geothermal power plants. Finally, an approximate analysis allowed to develop a new correlation for predicting the maximal specific power output of an ORC.