A biomass-fired micro-scale CHP system with organic Rankine cycle (ORC) – Thermodynamic modelling studies

Organic Rankine cycle (ORC) systems are some of the most suitable technologies to produce electricity from low-temperature waste heat. In this study, a non-regenerative, micro-scale ORC system was tested in off-design conditions using R134a as the working fluid. The experimental data were then used to tune the semi-empirical models of the main components of the system. Eventually, the models were used in a component-oriented system solver to map the system electric performance at varying operating conditions. The analysis highlighted the non-negligible impact of the plunger pump on the system performance Indeed, the experimental results showed that the low pump efficiency in the investigated operating range can lead to negative net electric power in some working conditions. For most data points, the expander and the pump isentropic efficiencies are found in the approximate ranges of 35% to 55% and 17% to 34%, respectively. Furthermore, the maximum net electric power was about 200 W with a net electric efficiency of about 1.2%, thus also stressing the importance of a proper selection of the pump for waste heat recovery applications.

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Experimental study of a micro-scale solar organic Rankine cycle system based on compound cylindrical Fresnel lens solar concentrator

Science China Technological Sciences ◽

10.1007/s11431-019-9562-4 ◽

2019 ◽

Vol 62 (12) ◽

pp. 2184-2194 ◽

Cited By ~ 1

Author(s):

Jia Meng ◽

PanPan Song ◽

MingShan Wei ◽

GuoHong Tian ◽

Meng Zhao ◽

...

Keyword(s):

Experimental Study ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Fresnel Lens ◽

Solar Concentrator ◽

Micro Scale ◽

Cycle System

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Design, Analysis and Optimization of a Micro-CHP System Based on Organic Rankine Cycle for Ultralow Grade Thermal Energy Recovery

Journal of Energy Resources Technology ◽

10.1115/1.4024858 ◽

2013 ◽

Vol 136 (1) ◽

Cited By ~ 18

Author(s):

Davide Ziviani ◽

Asfaw Beyene ◽

Mauro Venturini

Keyword(s):

Heat Exchanger ◽

Simulation Model ◽

Thermal Energy ◽

Energy Recovery ◽

Organic Rankine Cycle ◽

Residential Building ◽

Rankine Cycle ◽

Hot Water ◽

Solar Thermal Energy ◽

Chp System

This paper presents the results of the application of an advanced thermodynamic model developed by the authors for the simulation of Organic Rankine Cycles (ORCs). The model allows ORC simulation both for steady and transient analysis. The expander, selected to be a scroll expander, is modeled in detail by decomposing the behavior of the fluid stream into several steps. The energy source is coupled with the system through a plate heat exchanger (PHE), which is modeled using an iterative sub-heat exchanger modeling approach. The considered ORC system uses solar thermal energy for ultralow grade thermal energy recovery. The simulation model is used to investigate the influence of ORC characteristic parameters related to the working medium, hot reservoir and component efficiencies for the purpose of optimizing the ORC system efficiency and power output. Moreover, dynamic response of the ORC is also evaluated for two scenarios, i.e. (i) supplying electricity for a typical residential user and (ii) being driven by a hot reservoir. Finally, the simulation model is used to evaluate ORC capability to meet electric, thermal and cooling loads of a single residential building, for typical temperatures of the hot water exiting from a solar collector.

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